The speed of the boat going with a current is 20 mph. When the boat goes against the current, the speed is 16 mph. Find the speed of the boat in still water and the speed of the current.

Answer:

[tex]\displaystyle x = \frac{\pi}{4} + k\, \pi[/tex] for integer [tex]k[/tex] (including negative numbers.)

Step-by-step explanation:

Pythagorean Identity: [tex]\sin^{2}(x) + \cos^{2}(x) = 1[/tex]. Equivalently, [tex]\cos^{2}(x) = 1 - \sin^{2}(x)[/tex].

Rewrite the original equation and apply this substitution to eliminate [tex]\cos(x)[/tex]:

[tex]\displaystyle \sin^{6}(x) + \cos^{6}(x) = \frac{1}{4}[/tex].

[tex]\displaystyle (\sin^{2}(x))^{3} + (\cos^{2}(x))^{3} = \frac{1}{4}[/tex].

[tex]\displaystyle (\sin^{2}(x))^{3} + (1 - \sin^{2}(x))^{3} = \frac{1}{4}[/tex].

Let [tex]y = \sin(x)[/tex] ([tex]-1 \le y \le 1[/tex].) The original equation is equivalent to the following equation about [tex]y[/tex]:

[tex]\displaystyle y^{6} + (1 - y^{2})^{3} = \frac{1}{4}[/tex].

Expand the cubic binomial in the equation:

[tex]\displaystyle y^{6} + 1 - 3\, y^{2} + 3\, (y^{2})^{2} - (y^{2})^{3} = \frac{1}{4}[/tex].

[tex]\displaystyle y^{6} + 1 - 3\, y^{2} + 3\, y^{4} - y^{6} = \frac{1}{4}[/tex].

Simplify to obtain:

[tex]\displaystyle 1 - 3\, y^{2} + 3\, y^{4} = \frac{1}{4}[/tex].

Rearrange and simplify:

[tex]12\, y^{4} - 12\, y^{2} + 3 = 0[/tex].

[tex]3\, (2\, y^{2} - 1)^{2} = 0[/tex].

[tex]2\, y^{2} - 1 = 0[/tex].

[tex]\displaystyle y^{2} - \frac{1}{2} = 0[/tex].

Solve for [tex]y[/tex]:

Either [tex]\displaystyle y = \frac{1}{\sqrt{2}}[/tex] or [tex]\displaystyle y = -\frac{1}{\sqrt{2}}[/tex].

If [tex]\displaystyle \sin(x) = y = \frac{1}{\sqrt{2}}[/tex], then [tex]\displaystyle x = \frac{\pi}{4} + 2\, k\,\pi[/tex] for all [tex]k\in \mathbb{Z}[/tex].

On the other hand, if [tex]\displaystyle \sin(x) = y = \frac{1}{\sqrt{2}}[/tex], then [tex]\displaystyle x = \frac{3\, \pi}{4} + 2\, k\,\pi = \frac{\pi}{4} + (2\, k + 1) \, \pi[/tex] for all [tex]k\in \mathbb{Z}[/tex].

Combine both situations to obtain:

[tex]\displaystyle x = \frac{\pi}{4} + 2\, k\, \pi[/tex] for all [tex]k \in \mathbb{Z}[/tex].

Answer:

The choose (C)

F(x)=x/ (x+1)(x-2)

The question is incomplete. The complete question is :

Let [tex]p(t) = -0.0375t^2 + 0.225t[/tex]  be the density function for the shelf life of a brand of banana which lasts up to 4 weeks. Time, t, is measured in weeks and [tex]$0 \leq t \leq 4$[/tex]. Incorrect answer icon Your answer is incorrect. Find the mean shelf life of a banana using . Round your answer to one decimal place.

Answer:

2.4

Step-by-step explanation:

 Given :

[tex]p(t) = -0.0375t^2 + 0.225t[/tex]

Mean :

[tex]$=\int_0^4 tp (t) \ dt$[/tex]

[tex]$=\int_0^4 t (0.0375 t^2 + 0.225t) \ dt$[/tex]

[tex]$=-0.0375 \int_0^4 t^3 \ dt + 0.225 \int_0^4 t^2 \ dt$[/tex]

[tex]$=-0.0375 \left[ \frac{t^4}{4} \right]^4_0 + 0.225 \left[ \frac{t^3}{3} \right]^4_0$[/tex]

[tex]$=-0.0375 (64) + 0.225 \left( \frac{64}{3} \right)$[/tex]

[tex]$=-2.5 + 4.8$[/tex]

= 2.4

Therefore, the mean is 2.4

Answer:

2552cm^2

Step-by-step explanation:

C.S.A=1320cm^2 ;r=?

h=15cm.

[C.S.A. = 2πrh]

(r=1320×7/660=14cm)

Now,

TSA of cylinder = 2πr (h + r) sq

TSA=2×22/7(15+14)=2552cm^2

Answer:

[tex]\frac{16}{81}[/tex]

Step-by-step explanation:

[tex](\frac{27}{8} )^{-\frac{4}{3} }[/tex]

[tex]=((\frac{3}{2} )^3)^{-4/3}[/tex]

[tex]=(\frac{3}{2} )^{-4}[/tex]

[tex]=(\frac{2}{3} )^{4}[/tex]

[tex]=\frac{16}{81}[/tex]

Answer:

16/81

Step-by-step explanation:

a negative exponent means 1/...

the number in the numerator means "to the power of".

the number in the denominator means take the root of that power.

so, we have to take the third root of the expression, or this then to the power of 4, and finally build 1/... if the whole result.

and the sequence is not making a difference.

the third root of of 27/8 = 3/2

this to the power of 4 = 81/16

this 1/... = 16/81

Answer:

the answer will be

1.2x10⁴

hope it helps

Answer:

We have been provided the number, 3430000. Therefore, the standard form is, 3430000=3.43×106, here, we have moved 6 places to the left. Hence, the standard form of 3430000 is 3.43×106. Note: It is important to note that the standard form of representing numbers is also called scientific form or standard index form.

Answer:

So if PT=TQ and TQ=7x-9

PT=5x+3=TQ=7x-9

5x+3=7x-9

minus 5x both sides

3=2x-9

add 9 both sides

12=2x

divide 2

6=x

PT=5x+3

PT=5(6)+3

PT=30+3

PT=33

PT=QT=33

x=6

Answer:

Step-by-step explanation:

0.9*2b = 1.8b

0.9*-1 = -0.9

So far we have 1.8b-0.9. It can't be simplified further.

Then, we add the 2nd part, -0.5b+1.

We have:

1.8b-0.9-0.5b+1. Next we combine like terms.

1.8b-0.5b = 1.3b.

-0.9+1 = 0.1

Then we put it together.

1.3b+0.1 is our answer.

Hope this helped! Have a nice day :D

Hi there!  

»»————-　★　————-««

I believe your answer is:

1.3b + 0.1

»»————-　★　————-««  

Here’s why:  

⸻⸻⸻⸻

[tex]\boxed{\text{Simplifying...}}\\\\0.9(2b-1)-0.5b+1\\--------------\\\rightarrow 1.8b - 0.9 - 0.5b + 1\\\\\rightarrow 1.8b - 0.5b - 0.9 + 1\\\\\rightarrow \boxed{1.3b +0.1}[/tex]

⸻⸻⸻⸻

»»————-　★　————-««  

Hope this helps you. I apologize if it’s incorrect.  

Answer:

a = 56.3°

Step-by-step explanation:

tan(a) = 9/6 = 1.5

atan(1.5) = 56.31°

Answer:

[tex]\boxed {\boxed {\sf 56.3 \textdegree}}[/tex]

Step-by-step explanation:

We are asked to find the measure of angle a.

This triangle is a right triangle because of the small triangle in the corner representing a 90 degree or right angle. Therefore, we can use trigonometric functions. The three main functions are:

The side measuring 6 is adjacent or next to angle a. The side measuring 9 is opposite angle a. Therefore, we will use the tangent function.

[tex]tan \theta= \frac{ opposite}{adjacent}[/tex]

[tex]tan \ a = \frac{ 9}{6}[/tex]

Since we are solving for an angle measure, we use the inverse trigonometric function.

[tex]tan ^{-1} * tan \ a = tan ^{-1} * \frac{9}6}[/tex]

[tex]a= tan ^{-1} * \frac{9}6}[/tex]

[tex]a= 56.30993247[/tex]

Round to the nearest tenth. The 0 in the hundredth place tells us to leave the 3 in the tenth place.

[tex]a \approx 56.3[/tex]

The measure of angle a is approximately 56.3 degrees.

Answer:

$1272.36 ( average weekly sales for first 3 weeks )

Step-by-step explanation:

weekly online sales = S(t)

Determine average weekly sales for first 3 weeks

S(t) = 2e^t

total sales = ∫ S(t) dt        

∴ Average weekly sales for first 3 weeks  ( note : S(t) = 2e^t  )

=  [tex]\int\limits^3_0 {2e^t \, dt / ( 3 - 0 )[/tex]            

= 2 [ e^t ] ³₀ / 3 = 2 ( e^3 - e^0 ) / 3 =  2 ( 6.3618 ) = 12.7236 hundreds

= $1272.36 ( average weekly sales for first 3 weeks )

Answer:

(b) It is symmetrical about [tex]x = 1[/tex]

Step-by-step explanation:

Given

[tex]y = 2(x - 1)^2 - 5[/tex]

See attachment for options

Required

True statement about the graph

First, we check the line of symmetric

[tex]y = 2(x - 1)^2 - 5[/tex]

Expand

[tex]y = 2(x^2 - 2x + 1) - 5[/tex]

Open bracket

[tex]y = 2x^2 - 4x + 2 - 5[/tex]

[tex]y = 2x^2 - 4x -3[/tex]

A quadratic equation [tex]y = ax^2 + bx + c[/tex] has the following line of symmetry

[tex]x = -\frac{b}{2a}[/tex]

By comparison, the equation becomes:

[tex]x = -\frac{-4}{2*2}[/tex]

[tex]x = \frac{4}{4}[/tex]

[tex]x = 1[/tex]

Hence, the line of symmetry is at: [tex]x = 1[/tex]

(b) is true.

Answer: It is symmetrical about x=1

Step-by-step explanation:

Answer:

Step-by-step explanation:

Sum of those 4 integers is:

If the smallest ones are 1, 2 and 3, then the greatest possible integer is:

Answer:

Step-by-step explanation:

B OR TRUE

Answer:

600

Step-by-step explanation:

Volume=l*b*h=5*12*10=600

Answer:

Which one have same variable gather or decrease up

Step-by-step explanation:

2x^2-4.6x^2=1.4x^2

-7x+7x=0

1.4x^2+2<0

x<0

Answer:

I think it's D

Step-by-step explanation:

Answer:  I think its D

Step-by-step explanation:

Rigid transformation moves a shape without changing the size of the shape.

See attachment for the diagram that shows the position of D'

Answer:

Step-by-step explanation:

the answer is b

Answer:

48.5 ft

Step-by-step explanation:

Answer:

no it's not a defined state it's undefined

Answer:

Step-by-step explanation:

[tex]f(x)=\frac{x+9}{7-4x} \\put ~f(x)=y\\flip~x~and~y\\f(y)=x\\y=f^{-1}(x)\\y=\frac{x+9}{7-4x} \\flip~x~and~y\\x=\frac{y+9}{7-4y} \\x(7-4y)=y+9\\7x-4xy=y+9\\-4xy-y=9-7x\\or\\4xy+y=7x-9\\y(4x+1)=7x-9\\y=\frac{7x-9}{4x+1} \\or~f^{-1}(x)=\frac{7x-9}{4x+1}[/tex]

Answer:

C.47,5cm²

Step-by-step explanation:

[tex]\\ \sf\longmapsto f(2+h)[/tex]

[tex]\\ \sf\longmapsto 4(2+h)-3[/tex]

[tex]\\ \sf\longmapsto 4h+8-3[/tex]

[tex]\\ \sf\longmapsto 4h+5[/tex]

Answer:

Step-by-step explanation:

The standard form for a circle is

[tex](x-h)^2+(y-k)^2=r^2[/tex] and what's important here is that the x- and the y- remain that way in the equation. Filling in our values,

[tex](x-(6))^2+(y-(-3))^2=25[/tex] which tells us that our center is

        6      and     -3 -------------------> (6, -3)

The radius is the square root of 25 which is 5.

Answer:

0.48

Step-by-step explanation:

hope it can work for you mark me as a brain liest

Given that :

Diameter (d) = 18 cm

Pi (π) = 3.14

Radius (r) = d/2 = 18/2 = 9 cm

We know that volume of sphere is

Volume of Sphere = 4/3πr³

Volume = 4/3 × 3.14 × (9)³

Volume = 4/3 × 3.14 × 729

Volume = 4 × 3.14 × 243

Volume = 12.56 × 243

Volume = 3052.08

Hence, the volume is 3052.08 cm³

Answer:

a union b= {1,2,3,4,5}

a intersection b ={2,3}

Step-by-step explanation:

The union of two sets A and B is a set that contains all the elements of A and B and is denoted by A U B

the set composed of all elements that belong to both A and B is A intersection B (A ∩ B)

Answer:

easy

Step-by-step explanation:

4ab³6a²b

Answer:

[tex] \frac{12 {a}^{2} {b}^{3} 6 {a}^{2}b }{3ab} \\ thank \: you[/tex]

Answer:

Step-by-step explanation:

I am not sure what your first inequality is saying y≤2x +7 or y≥2x+7

-the equation y> -3x-2 , has a negative slope m= -3 (the line is going down from left to right if is a negative slope) and it has to be a dotted line( <, or > is a dotted line, ≤, or ≥ is a solid line) so the answer must be either A or D

-if the second equation is y≤2x +7 then the answer is D because y has to be less than 2x+7 the area under the line will be include in the solution

--if the second equation is y≤2x +7 then the answer is A because y has to be greater than 2x+7 the area above the line will be include in the solution

Answer:

1 4/5

Step-by-step explanation:

2x+7>-3x-2

2x+3x>-2-7

5x/5>-9/5

=1 4/5

Thanks Hope It Help

Answer:

8 / sqrt(3)

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

tan theta = opp / adj

tan A = BC / AC

tan 30 = BC / 8

8 tan 30 = BC

8 * sqrt(3)/3 = BC

8/3 sqrt(3) = BC