What is the value of i 20+1?
1
- т т .-

Answer:  see proof below

Step-by-step explanation:

You will need the following identities to prove this:

[tex]\tan\ (\alpha-\beta)=\dfrac{\tan \alpha-\tan \beta}{1+\tan \alpha\cdot \tan \beta}[/tex]

[tex]\cos\ 2\alpha=\cos^2 \alpha-\sin^2\alpha[/tex]

LHS → RHS

[tex]\dfrac{2\tan\ (45^o-A)}{1+\tan^2\ (45^o-A)}\\\\\\=\dfrac{2\bigg(\dfrac{\tan\ 45^o-\tan\ A}{1+\tan\ 45^o\cdot \tan\ A}\bigg)}{1+\bigg(\dfrac{\tan\ 45^o-\tan\ A}{1+\tan\ 45^o\cdot \tan\ A}\bigg)^2}\\\\\\=\dfrac{2\bigg(\dfrac{1-\tan\ A}{1+\tan\ A}\bigg)}{1+\bigg(\dfrac{1-\tan\ A}{1+\tan\ A}\bigg)^2}\\\\\\=\dfrac{2\bigg(\dfrac{1-\tan A}{1+\tan A}\bigg)}{1+\bigg(\dfrac{1-2\tan\A+\tan^2 A}{1+2\tan A+\tan^2A}\bigg)}\\[/tex]

[tex]=\dfrac{2\bigg(\dfrac{1-\tan A}{1+\tan A}\bigg)}{\dfrac{(1+2\tan A+\tan^2A)+(1-2\tan A+\tan^2 A)}{1+2\tan A+\tan^2A}}\\\\\\=\dfrac{2\bigg(\dfrac{1-\tan A}{1+\tan A}\bigg)}{\dfrac{2+2\tan^2A}{1+2\tan A+\tan^2A}}\\\\\\=\dfrac{2\bigg(\dfrac{1-\tan A}{1+\tan A}\bigg)}{2\bigg(\dfrac{1+\tan^2A}{(1+\tan A)^2}\bigg)}\\\\\\=\dfrac{\bigg(\dfrac{1-\tan A}{1+\tan A}\bigg)}{\bigg(\dfrac{1+\tan^2A}{(1+\tan A)^2}\bigg)}[/tex]

[tex]=\dfrac{1-\tan A}{1+\tan A}}\times \dfrac{(1+\tan A)^2}{1+\tan^2A}\\\\\\=\dfrac{1-\tan^2 A}{1+\tan^2 A}\\\\\\=\dfrac{1-\dfrac{\sin^2 A}{\cos^2 A}}{1+\dfrac{\sin^2 A}{\cos^2 A}}\\\\\\=\dfrac{\bigg(\dfrac{\cos^2 A-\sin^2 A}{\cos^2 A}\bigg)}{\bigg(\dfrac{\cos^2 A+\sin^2 A}{\cos^2 A}\bigg)}\\\\\\=\dfrac{\cos^2 A-\sin^2 A}{\cos^2 A+\sin^2 A}\\\\\\=\dfrac{\cos^2 A-\sin^2 A}{1}\\\\\\=\cos^2 A-\sin^2 A\\\\\\=\cos 2A[/tex]

cos 2A = cos 2A   [tex]\checkmark[/tex]

Answer:

380 cm^2

Step-by-step explanation:

10*10=100(base square)

Each triangle= (14*10) /2=70

4 sides, so therefore: 70*4=280

280+100=380

Since the square base has side 10 cm and triangular side has height 14 cm, the total surface area of square pyramid is 380 cm²

To answer the question, we need to find the total surface area of the square pyramid

Since a square pyramid has a square base and four triangular sides, its surface area, A = area of square base + 4 × Area of triangular side.

Area of square with side, L is A = L²

Area of triangle with height, h and base, L which is the length of the square base is A' = 1/2Lh

So, total surface area of square pyramid is A" = L² + 4 × 1/2Lh

= L² + 2Lh

Given that the length of the square base is 10 cm and the height of the triangular side is 14 cm.

We have that

So, substituting the values of the variables intot he equation, we have

A" = L² + 2Lh

A" = (10 cm)² + 2 × 10 cm × 14 cm

A" = 100 cm² + 280 cm²

A" = 380 cm²

So, the total surface area of square pyramid is 380 cm²

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Answer:

1st triangle:

sin(C): 0.64, [tex]\frac{16}{25}[/tex]

cos(C): 0.8, [tex]\frac{4}{5}[/tex]

Second triangle:

sin(C): 0.75, [tex]\frac{\sqrt{5} }{3}[/tex]

cos(C): 0.67, [tex]\frac{2}{3}[/tex]

Step-by-step explanation:

Using SOH CAH TOA, we know that to find the sin of an angle, it's Opposite/Hypotenuse.

To find the cos of an angle, it's adjacent/hypotenuse.

In the 1st triangle:

The adjacent to C is 16, the hypotenuse is 25.

[tex]\frac{16}{25} = 0.64[/tex] is the sin of C.

The adjacent to C is 20, and the hypotenuse is 25.

[tex]\frac{20}{25} = 0.8[/tex] is the cos of C.

In the second triangle:

The opposite to C is [tex]\sqrt{5}[/tex] and the hypotenuse is 2.

[tex]\frac{\sqrt{5} }{2} \approx0.75[/tex] is the sin of C.

The adjacent to C is 2 and the hypotenuse is 3.

[tex]\frac{2}{3} \approx 0.67[/tex] is the cos of C.

Hope this helped!

Answer:

k=-6

Step-by-step explanation:

Answer:

[tex]\Large \boxed{k=-6}}[/tex]

Step-by-step explanation:

35 = -5(2k+5)

Expand brackets.

35 = -10k - 25

Add 25 on both sides.

60 = -10k

Divide both sides by -10.

-6 = k

Answer: The solution for the system is (2, -7)

Step-by-step explanation:

Ok, here we have linear relationships.

A linear relationship can be written as:

y = a*x + b

where a is the slope and b is the y-axis intercept.

For a line that passes through the points (x1, y1) and (x2, y2), the slope can be written as:

a = (y2 - y1)/(x2 - x1).

In this case, we have two lines:

ya, that passes through:

(-8, -5) and (-3, -6)

Then the slope is:

a = (-6 - (-5))/(-3 - (-8)) = (-6 + 5)/(-3 + 8) = -1/5

now, knowing one of the points like (-3, - 6) we can find the value of b.

y(x) = (-1/5)*x + b

y(-3) = -6 = (-1/5)*-3 + b

-6 = 3/5 + b

b = -6 - 3/5 = -33/5

then the first line is:

ya =  (-1/5)*x  -33/5

For the second line, we know that it passes through the points:

(-8, -15) and (-3, -11)

Then the slope is:

a = (-11 - (-15))/(-3 -(-8)) = (-11 + 15)/(-3 + 8) = 4/5

The our line is:

y(x) = (4/5)*x + b

and for b, we do the same as above, using one of the points, for example (-3, -11)

y(-3) = -11 = (4/5)*-3 + b

b = -11 + 12/5 = -(55 + 12)/5 = -43/5

then:

yb = (4/5)*x - 43/5.

Ok, our system of equations is:

ya = (-1/5)*x  -33/5

yb = (4/5)*x - 43/5.

To solve this, we suppose ya = yb

then:

(-1/5)*x + -33/5 = (4/5)*x - 43/5.

-33/5 + 43/5 = (4/5)*x + (1/5)*x

10/5 = 2 = (4/5 + 1/5)*x = x

2 = x

now we evaluate x = 2 in one of the lines:

ya = (-1/5)*2 -33/5 = -2/5 - 33/5 = -35/5 = -7

Then the lines intersect at the point (2, - 7), which is the solution for the system.

Answer:

-6723cw

Step by Step:

(-3c * 3w * 5) * 3 - 9c * 6w* 8 - 9c * 9w * 15 - 27c * 6w * 8 - 27c * 9w * 15

Answer:

x=4      or    x= - 16

Step-by-step explanation:

|x+6|

Now subtract 7 which equals to 3.

|x+6|-7=3

|x+6|=10

Now remove the mode by adding plus minus sign in the front of 10.

x+6=±10

x+6=10 or x+6=-10

x=4      or x=-16

Answer:

6

Step-by-step explanation:

If a number and a variable were together in a term, the number would the the coefficient. The coefficient would multiply the variable.

In '6x', the number '6' is the coefficient. '6' would be multiplying 'x'.

The correct answer should be 6.  

Answer:

Area: [tex]50\pi -100[/tex]

Perimeter: 20[tex]\pi[/tex]

Step-by-step explanation:

If we take half of one of these "pedals" we can see that it is simply 1/4 of a circle with radius 5, subtracted by a triangle. Let's calculate this half-pedal.

[tex]1/4(25 \pi) - 1/2(5* 5)[/tex]

That means 4 pedals is equal to:

[tex]8(1/4(25\pi) - 1/2 (25))[/tex]

[tex]50\pi - 100[/tex]

So.. The area of the shaded region is [tex]50\pi -100[/tex]

Perimeter is even simpler. the half-pedal is just 1/4 of the circumference of the circle. The circumference is just [tex]10\pi[/tex], which means our half pedal is:

[tex]1/4(10\pi )[/tex]

Multiplying by 8, our perimeter is just 20[tex]\pi[/tex].

Answer:

sqrt of (m-7) = n+3

m = (n+3)^2 + 7 or m= n^2 + 6n + 16

sqrt of (m)-7 = n+3

m = (n+10)^2 or m =n^2 + 20n + 100

Step-by-step explanation:

(2) move the constants to the other side, and square

or  (1) square and move constants

then you can solve for m

Answer:

[tex]n^2+6n+16[/tex]

Step-by-step explanation:

I'm going to assume you meant [tex]\sqrt{m-7} = n+3[/tex], not  [tex]\sqrt{m} - 7 = n+3[/tex].

[tex](\sqrt{m-7}) ^2 = (n+3)^2\\\\(\sqrt{m-7}^2) = (n+3)^2\\\\(m-7)^{\frac{2}{2} } = (n+3)^2\\\\m - 7 = (n+3)^2\\\\m - 7 = n^2 + 2n\cdot3 + 3^2\\\\m - 7 = n^2 + 6n + 9\\\\m - 7 + 7 = n^2 + 6n + 9 + 7\\\\m = n^2 + 6n + 16[/tex]

Hope this helped!

Answer:

x = 69°

Step-by-step explanation:

1). JFGHI is a pentagon, every angle in a Pentagon is equal to 108°.

2). angle JIH + angle HIE = 180°; angle JIH = 108, so angle HIE = 72°.

3).  angle JDI is equal to 39° and angle IEH; so angle IEH = 39°

4). Now we know 2 out of the three angles in the triangle IHE, so we can find x!

5). x + angle HIE + angle IEH = 180°

    x + 72° + 39° = 180°

    x = 69°

Answer:

x = 180 - [(180 - 3x) + (180 - 2x)]

Step-by-step explanation:

Start off by finding the angles of the triangle

Angle F = 180 - 3x

The angle across from I (which I will call I) = 180 - 2x

Angle G = 180 - (F + I)

Now that we know what G is, we know what x is because the Alternate Exterior Angles Theorem states that if a pair of parallel lines are cut by a transversal, then the alternate exterior angles are congruent. So pretty much X = G

Therefore x =  180 - (F + I) or otherwise said as:

x = 180 - [(180 - 3x) + (180 - 2x)]

I hope this is helpful :)

Answer:

The first one

Step-by-step explanation:

This line is the best fit for the scatter plot because it touches a lot more points than the second

Answer:

The first line

Step-by-step explanation:

Hey there!

Well the first lie is a positive slope just like the dots whereas,

the second line is a negative slope.

Therefore, the first line is the line of best fit.

Hope this helps :)

Answer:

x >= -7  ................(1a)

x >= 3   ...............(2a1)

Step-by-step explanation:

f(x) =  [tex]\sqrt{x+7}-\sqrt{x^2+2x-15}[/tex]  .............(0)

find the domain.

To find the (real) domain, we need to ensure that each term remains a real number.

which means the following conditions must be met

x+7 >= 0  .....................(1)

AND

x^2+2x-15 >= 0 ..........(2)

To satisfy (1),  x >= -7  .....................(1a) by transposition of (1)

To satisfy (2), we need first to find the roots of (2)

factor (2)

(x+5)(x-3) >= 0

This implis

(x+5) >= 0 AND (x-3) >= 0.....................(2a)

OR

(x+5) <= 0 AND (x-3) <= 0 ...................(2b)

(2a) is satisfied with x >= 3   ...............(2a1)

(2b) is satisfied with x <= -5 ................(2b1)

Combine the conditions (1a), (2a1), and (2b1),

x >= -7  ................(1a)

AND

(

x >= 3   ...............(2a1)

OR

x <= -5 ................(2b1)

)

which expands to

(1a) and (2a1)   OR  (1a) and (2b1)

( x >= -7 and x >= 3 )  OR ( x >= -7 and x <= -5 )

Simplifying, we have

x >= 3  OR ( -7 <= x <= -5 )

Referring to attached figure, the domain is indicated in dark (purple), the red-brown and white regions satisfiy only one of the two conditions.

Answer:

The correct ans is..... ( which i believe )

3rd option

Hope this helps...

Pls mark my ans as brainliest

If u mark my ans as brainliest u will get 3 extra points

Answer:

3rd option

Step-by-step explanation:

because 2/5 of 40 is equal to 16, and thats the equivelent of the pants sold.

Answer:

The correct option is;

Left object volume = right object volume

Step-by-step explanation:

The shapes given in the question are two circular cones that have equal base radius and equal height

The formula for the volume, V of a circular cone = 1/3 × Base area × Height

The base area of the two shapes are for the left A = π·r², for the right A = π·r²

The heights are the same, therefore, the volume are;

For the left

[tex]V_{left}[/tex] = 1/3×π·r²×h

For the right

[tex]V_{right}[/tex] = 1/3×π·r²×h

Which shows that

1/3×π·r²×h  = 1/3×π·r²×h and [tex]V_{left}[/tex]  = [tex]V_{right}[/tex], therefore, the volumes are equal and the correct option is left object volume = right object volume.

Answer:

8.3

Step-by-step explanation:

To do this use the distance formula

[tex]d = \sqrt{(x2-x1)^2+(y2-y1)^2}[/tex]

First find the coordinates Jane (-5, -2) Friend (3, -4)

Now solve for d (8.246)

Answer:

10 units or approx. 8.25 units

Step-by-step explanation:

Jane's house is at coordinate (-5,-2) and her friend's house is at coordinate (3,-4).

You can find the answer in 2 ways.

1) Hypotenuse (the diagonal side or side across from the right angle) - approx. 8.25 units

2) Down and Side (go down 2 units and go side 8 units) - 10 units

Hope that helps and maybe earns a brainliest!

Have great day ahead! :)

Answer:

[tex]\Large \boxed{b=2}[/tex]

Step-by-step explanation:

-5+2(10b-2)=31

Expand brackets.

-5+20b-4=31

-9+20b=31

Add 9 on both sides.

20b=40

Divide both sides by 20

b=2

Answer:

Step-by-step explanation:

-5+2(10b-2)=31

Multiply the terms in the bracket

That's

- 5 + 20b - 4 = 31

Group like terms

Send the constants to the right side of the equation

That's

20b = 31 + 4 + 5

Simplify

20b = 40

Divide both sides by 20

We have the final answer as

Hope this helps you

The exponent 7 tells us how many copies of "8" are being multiplied together.

The expression 8*8*8 is equal to 8^3, while 8*8*8*8 = 8^4

Multiplying 8^3 and 8^4 will have us add the exponents to get 8^7. The base stays at 8 the entire time.

The rule is a^b*a^c = a^(b+c) where the base is 'a' the entire time.

Answer:

8^ 7

Step-by-step explanation:

(8*8*8) * (8*8*8*8)

There are 3 8's times 4 8's

8^3 * 8^4

We know that a^b * a^c = a^ (b+c)

8 ^ ( 3+4)

8^ 7

Answer:

1. EF = 65m

2. DF = 73m

Step-by-step explanation:

1. EF = height of the building = h = 33 / tan 27 = 65m

2. DF = sqrt (65² + 33²) = 73m

The building is 64.76 meters long and 73 meters far from the top of the building to the tip of the shadow.

From the triangle DEF, we find the value of EF by using tan function.

tan function is a ratio of opposite side and adjacent side.

tan(27)= 33/FE

0.5095 = 33/FE

Apply cross multiplication:

FE=33/0.5095

FE=64.76

Now DF is the hypotenuse, we find it by using pythagoras theorem.

DF²=DE²+EF²

DF²=33²+64.76²

DF²=1089+4193.85

DF²=5282.85

Take square root on both sides:

DF=72.68

In a triangle the the sum of three angles is 180 degrees.

∠D + 27 +90 =180

∠D + 117 =180

Subtract 117 from both sides:

∠D =63 degrees.

Hence, the building is 64.76 meters long and 73 meters far from the top of the building to the tip of the shadow.

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Hey there! I'm happy to help!

The vertex form of a parabola is y=a(x-h)²+k. The h represents the horizontal transformation, while the k represents the vertical. The vertex of a parabola in this form is (h,k). The a represents a vertical stretch or shrink.

Our parabola is y=(x+1)²+2. This is already in vertex form, so we do not need to change the equation. There is no a (basically a=1), which means that the parabola has not been stretched or shrunk from its parent form.

We see that the h is -1. This is because in the original equation it is (x-h)², so it has to be -1 because the two negatives make a positive which is the +1. (x--1)=(x+1).

We see that the k value is 2.

Since the vertex is (h,k), this vertex is (-1,2).

However, we have to shift the parabola 7 units to the right and 5 units down. So, we add 7 to the x-value and subtract 5 from the y-value of the vertex.

(x,y)⇒(x+7,y-5)

(-1,2)⇒(6,-3)

Therefore, the vertex of the resulting parabola is (6,-3).

Have a wonderful day! :D

Answer:

convert them to decimasls

Step-by-step explanation:

convert thhem to decimals to make it easier

Answer:

1/2 2/4 4/8 6/12 9/18

Step-by-step explanation:

Answer:

20

Step-by-step explanation:

We know that ΔBAC and ΔBED are similar becuase of the AA Postulate (they both have a right angle and they both share ∠B). Since AC is 15/3 = 5 times longer than ED, the scale factor is 5 which means AB is 5 times longer than EB. This makes EB = 25 / 5 = 5. Since AB = AE + EB and we know that AB = 25, AE = x and EB = 5, 25 = x + 5 which means x = 20.

Answer:

she bought 7 cards

Step-by-step explanation

7x5=35 and im sure there is tax

Answer:

[tex]\sqrt{\frac{x+2}{-4} }+3=y[/tex] d=(-infinity,-2) r=(3,+infinity)

Step-by-step explanation:

i did the math

Answer:

6×[tex]10^{-4}[/tex]

Step-by-step explanation:

Answer:

1 1/2 miles / hour

Step-by-step explanation:

We want distance / time

3/4 miles

---------------

1/2 hour

3/4 ÷ 1/2

Copy dot flip

3/4 * 2/1

3/2

1 1/2 miles / hour

Answer:

D

Step-by-step explanation:

Multiple (3/4)  by 2 to find the information for one hour)

6/4 in one hour

3/2 or 1 + 1/2 mi/h

D is the answer

Answer:

d = √8

d ≈ 2.82843

Step-by-step explanation:

Distance Formula: [tex]d = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2}[/tex]

Simply plug in our coordinates into the distance formula:

[tex]d = \sqrt{(-3 + 5)^2+(-8 + 6)^2}[/tex]

[tex]d = \sqrt{(2)^2+(-2)^2}[/tex]

[tex]d = \sqrt{4+4}[/tex]

[tex]d = \sqrt{8}[/tex]

To find the decimal, simply evaluate the square root:

√8 = 2.82843

Answer:

Step-by-step explanation:

Let the points be A and B

A ( - 5 , - 6 ) ⇒ ( x₁ , y₁ )

B ( -3 , - 8 )⇒( x₂ , y₂ )

Now, let's find the distance between these two points:

AB = [tex] \mathsf{ \sqrt{ {(x2 - x1)}^{2} + {(y2 - y1)}^{2} } }[/tex]

Plug the values

⇒[tex] \mathsf{ \sqrt{( - 3 - ( - 5) )^{2} + {( - 8 - ( - 6))}^{2} } }[/tex]

When there is a ( - ) in front of an expression in parentheses, change the sign of each term in the expression

⇒[tex] \mathsf{ \sqrt{ {( - 3 + 5)}^{2} + {( - 8 + 6)}^{2} } }[/tex]

Calculate

⇒[tex] \mathsf{ \sqrt{ {(2)}^{2} + {( - 2)}^{2} } }[/tex]

Evaluate the power

⇒[tex] \mathsf{ \sqrt{4 + 4} }[/tex]

Add the numbers

⇒[tex] \mathsf{\sqrt{8} }[/tex]

Simplify the radical expression

⇒[tex] \mathsf{ \sqrt{2 \times 2 \times 2}} [/tex]

⇒[tex] \mathsf{2 \sqrt{2} }[/tex] units

Hope I helped!

Best regards!

Answer:

Simple division..

divide 5 by 3,678

you'll get answer

0.00135943447

●✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎❀✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎●

      Hi my lil bunny!

❧⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯⎯☙

[tex]5\ \div \ 3678[/tex]

[tex]= \frac{5}{3678}[/tex] (Decimal: 0.001359)

●✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎❀✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎✴︎●

If this helped you, could you maybe give brainliest..?

❀*May*❀

Triangle inequality theorem:

In any triangle, the length of any side must be:

For the problem you have:

x must be greater than 8.0 - 2.5 and less than 8.0 + 2.5

5.5 < x < 10.5

Answer:

5.5<x<10.5

Step-by-step explanation: