PROVE THAT:
cos 20° - sin 20° = \sqrt{2}sin25°
Answer:
See below.
Step-by-step explanation:
[tex]\cos(20)-\sin(20)=\sqrt{2}\sin(25)[/tex]
First, use the co-function identity:
[tex]\sin(90-x)=\cos(x)[/tex]
We can turn the second term into cosine:
[tex]\sin(20)=\sin(90-70)=\cos(70)[/tex]
Substitute:
[tex]\cos(20)-\cos(70)=\sqrt{2}\sin(25)[/tex]
Now, use the sum to product formulas. We will use the following:
[tex]\cos(x)-\cos(y)=-2\sin(\frac{x+y}{2})\sin(\frac{x-y}{2})[/tex]
Substitute:
[tex]\cos(20)-\cos(70)=-2\sin(\frac{20+70}{2})\sin(\frac{20-70}{2})\\\cos(20)-\cos(70) =-2\sin(45)\sin(-25)\\\cos(20)-\cos(70)=-2(\frac{\sqrt{2}}{2})\sin(-25)\\ \cos(20)-\cos(70)=-\sqrt{2}\sin(-25)[/tex]
Use the even-odd identity:
[tex]\sin(-x)=-\sin(x)[/tex]
Therefore:
[tex]\cos(20)-\cos(70)=-\sqrt{2}\sin(-25)\\\cos(20)-\cos(70)=-\sqrt{2}\cdot-\sin(25)\\\cos(20)-\cos(70)=\sqrt{2}\sin(25)[/tex]
Replace the second term with the original term:
[tex]\cos(20)-\sin(20)=\sqrt{2}\sin(25)[/tex]
Proof complete.
Archer receives a day's work of pay, p, for 5 days of mowing lawns. He spent half of his money on gas. Then he spent $5 on water. Now, he has $40 left. Which equation represents how much Archer would get paid each day of mowing lawns?
Answer:
Daily pay= $18
5 days pay = $90
Step-by-step explanation:
Archer's daily pay =p
Pay for 5 days= 5p
Gas = 1/2 of 5p
= 1/2 × 5p
= 5p/2
Water = $5
Balance = $40
5p = 5/2p + 5 + 40
5p - 5/2p = 45
10p -5p /2 = 45
5/2p = 45
p= 45÷ 5/2
= 45 × 2/5
= 90/5
P= $18
5p= 5 × $18
=$90
The equation to determine Archer's daily pay is
5p = 5/2p + 5 + 40
Divide both sides by 5
p = 5/2p + 45 ÷ 5
= (5/2p + 45) / 5
p= (5/2p + 45) / 5
Please answer it now
Answer:
8
Step-by-step explanation:
x+37+x+37+90 = 180
2x + 74 = 90
2x = 16
x = 8
Answer:
x=8°
Step-by-step explanation:
JI is a diameter and K is on the circumference of a circle.
∴∠JKI=90°
also KJ=KI=x(say)
tan (x+37)=y/y=1=tan 45
so x+37=45
x=45-37=8°
Find the value of x.
Answer:
x = 20
Step-by-step explanation:
Intersecting Chords Theorem: ab = cd
Step 1: Label our variables
a = x
b = x - 11
c = x - 8
d = x - 5
Step 2: Plug into theorem
x(x - 11) = (x - 5)(x - 8)
Step 3: Solve for x
x² - 11x = x² - 8x - 5x + 40
x² - 11x = x² - 13x + 40
-11x = -13x + 40
2x = 40
x = 20
Answer: x=20
Step-by-step explanation:
[tex]ab=cd[/tex]
[tex]x(x - 11) = (x - 5)(x - 8)[/tex]
[tex]x^2 - 11x = x^2 - 13x + 40[/tex]
[tex]x^2 - 11x = x^2 - 8x - 5x + 40[/tex]
[tex]-11x = -13x + 40\\2x = 40\\x = 20[/tex]
A tank contains 15,000 L of brine with 24 kg of dissolved salt. Pure water enters the tank at a rate of 150 L/min. The solution is kept thoroughly mixed and drains from the tank at the same rate.How much salt is in the tank after t minutes
Answer:
Step-by-step explanation:
Let y(t) be the amount of salt in the tank after time t.
(A) Incoming rate = 0 (due to Pure water having no salt)
(B) Mixed solution comes out at 150 L/min. Initially the tank has 15,000 L of brine with 24 kg of salt.
concentration of salt at time t = y(t) / 15000 kg/L
Outgoing rate = y(t)/15000 * 150 = y(t) / 100
(C) we know that,
[tex]\frac{dy}{dx} =(incoming\ rate) - (outgoing\ rate)[/tex]
[tex]\frac{dy}{dx} =0-\frac{y(t)}{100} = \frac{-y(t)}{100}[/tex]
Separate variable and integrate
[tex]\int {\frac{dy}{y} } = - \int {\frac{1}{100} } \, dt[/tex]
[tex]ln|y|=-\frac{1}{100}t + D[/tex]
[tex]y=e^{D} e^{\frac{-t}{100} }[/tex]
[tex]y= Ce^{\frac{-t}{100} }\ [C=e^{D} ][/tex]
At t= 0 , y(0) = 24 kg
[tex]24=C\ e^{0}[/tex]
C= 24
(D) Therefore, the amount of salt in the tank after time t :
[tex]y(t)=24e^{\frac{-t}{100} }\ kg[/tex]
What is the reason: if a+c=b+c then a=b
Step-by-step explanation:
Example 1:
a+c=b+c then a=b
First let the value of a and b be different (not equal)
a=5
b=7
c=10
a+c=b+c
5+10=7+10
15≠17
Example 2:
Let the value a and b be equal (the same)
a=5
b=5
c=10
a+c=b+c
5+10=5+10
15=15
So when,
a+c and b+c is equal, a and b are always equal.
Hope this helps ;) ❤❤❤
Answer:
a=b
Step-by-step explanation:
Reason:
a+c=b+c
a-b=c-c
c-c would be 0
if a-b=c-c=0
a-b=0
Only if a=b can a-b=0
You can also take it as:
b-a=c-c (a+c=b+c)
b-a=0=c-c
Therefore b=a
By the way even I am a BTS army
roberta is 6 times danielles age. in 12 years, roberta will only be 2 times danielles age. how old is danielle now?
Answer:
the answer is 3
Step-by-step explanation:
(x2 - 41)2 + (yz - Yı) to the find the length of the segment
62. Use the distance formula d =
from (6,0) and (-5, 4).
Answer:
√137
Step-by-step explanation:
[tex](x_1, y_1) = (6, 0)\\(x_2, y_2) = (-5, 4)\\\\d = \sqrt{(x_2-x_1)^2+(y_2-y_1)^2} \\d = \sqrt{(-5-6)^2+(4-0)^2}\\ d = \sqrt{(-11)^2+(4)^2}\\ d = \sqrt{121+16}\\ d = \sqrt{137}\: or \:11.7[/tex]
plz help.. plzz if you can
Answer:
C is a function
Step-by-step explanation:
We can use the vertical line test. If a vertical straight lines passes through the graph more than one, it is not a function
A and B are not functions
C is a function
Find the amplitude of y = -2 sin x
Answer:
Amplitude = 2
Step-by-step explanation:
The amplitude of this sine wave is 2 denoted by the coefficient -2 in front of the sin(x). The negative of the coefficient denotes that the sine wave is the opposite of the standard sine wave.
Cheers.
AB = 15, BC = 10, and CD= 7. Find the length DA.
451. Equilateral triangles BCP and CDQ are attached to the outside of regular pentagon
ABCDE. Is quadrilateral BPQD a parallelogram? Justify your answer.
Answer:
451. No, the angles are wrong.
Step-by-step explanation:
450. AB = 15, BC = 10, and CD= 7. Find the length DA.
This cannot be done without additional information about the sort of figure that ABCD is. If these are points on a line segment, we need to know their order. If these are points on a quadrilateral, we need to know its description in more detail.
If these are points ordered ABCD on a line, then AD = 15+10+7 = 32.
__
451. See the attached figure. BPQD is not a parallelogram: BCQ is not a straight line. (The internal angles of a pentagon are 108°, but would need to be 120° for BCQ to be a straight line, making BP parallel to DQ.) Instead, BPQD is an isosceles trapezoid.
5
What is the equation, in point-slope form, of the line that
is parallel to the given line and passes through the point
(-3, 1)?
4
3
2
(-3, 1)
42.27
1
5 4 3 2 1
2 3 4 5 x
y-1=-{(x+3)
y-1=-{(x + 3)
y-1= {(x + 3)
y-1= {(x + 3)
(-2, 4)
Answer: [tex]y-1=\dfrac32(x+3)[/tex]
Step-by-step explanation:
Slope of a line passes through (a,b) and (c,d) = [tex]\dfrac{d-b}{c-a}[/tex]
In graph(below) given line is passing through (-2,-4) and (2,2) .
Slope of the given line passing through (-2,-4) and (2,2) =[tex]\dfrac{-4-2}{-2-2}=\dfrac{-6}{-4}=\dfrac{3}{2}[/tex]
Since parallel lines have equal slope . That means slope of the required line would be .
Equation of a line passing through (a,b) and has slope m is given by :_
(y-b)=m(x-a)
Then, Equation of a line passing through(-3, 1) and has slope = is given by
[tex](y-1)=\dfrac32(x-(-3))\\\\\Rightarrow\ y-1=\dfrac32(x+3)[/tex]
Required equation: [tex]y-1=\dfrac32(x+3)[/tex]
Black Diamond Ski Resort charges $25 for ski rental and $10 an hour to ski. Bunny Hill Ski Resort charges $50 for ski rental and $5 an hour to ski. Create an equation to determine at what point the cost of both ski slopes is the same.
Answer:
25 + 10h = 50+5h
Step-by-step explanation:
Black Diamond Ski Resort
25 + 10h
Bunny Hill Ski Resort
50+5h
We want when they are equal
25 + 10h = 50+5h
Answer:
10x + 25 = 5x + 50
Step-by-step explanation:
Weather balloons burst at an altitude of 27.5 km. What is the altitude in meters?
Answer:
27500
Step-by-step explanation:
meters are 100 times more than kilometers hope this helps:)
The diagonal of rhombus measure 16 cm and 30 cm. Find it's perimeter
Answer:
P = 68 cmStep-by-step explanation:
The diagonals of the rhombus divide it into 4 congruent right triangles.
So we can use Pythagorean theorem to calculate side of a rhombus.
[tex](\frac e2)^2+(\frac f2)^2=s^2\\\\e=30\,cm\quad\implies\quad\frac e2=15\,cm\\\\f=16\,cm\quad\implies\quad\frac f2=8\,cm\\\\15^2+8^2=s^2\\\\s^2=225+64\\\\s^2=289\\\\s=17[/tex]
Perimeter:
P = 4s = 4•17 = 68 cm
Find the area of the following shape. Show all work
Best way to solve this is by using
[tex] \sqrt{s(s - a)(s - b)(s - c)} [/tex]
[tex]where \: s = \frac{a + b + c}{2} [/tex]
s=(12+8+17)/2
=18.5
using the formulae
area =43.5
Use slope-intercept form to graph each system of equations and solve each system.
Answer:
(0,3), graph is attached.
Step-by-step explanation:
We know that the first equation will increase 2 points in y for every 1 x, since the constant next to x is 2. We also know it's y-intercept will be 3.
As for the second equation, we know it will have no y and instead run through the y=3 line, crossing every value of x.
Graphing this, we see that these lines intersect at (0,3) so that's the solution to this system.
Hope this helped!
Select the equivalent expression,
(9^6*7^-9)^-4 =?
Choose 1 answer:
А
9^24*7^-36
B
9^24/7^36
C
7^36/9^24
Answer:
c
Step-by-step explanation:
The expression (9⁶ x 7⁻⁹)⁻⁴ is equivalent to expression 7³⁶ / 9²⁴. Then the correct option is D.
What is an equivalent expression?The equivalent is the expressions that are in different forms but are equal to the same value.
The expression is given below.
⇒ (9⁶ x 7⁻⁹)⁻⁴
Simplify the expression, we have
⇒ (9⁻⁶ x 7⁹)⁴
⇒ 9⁻²⁴ x 7³⁶
⇒ 7³⁶ / 9²⁴
Then the correct option is D.
More about the equivalent link is given below.
https://brainly.com/question/889935
#SPJ2
what is another expression equivalent to 3(8-2)
Answer:
3(6)
??
Step-by-step explanation:
The fuel efficiency of one type of car is recorded in a scatterplot where the amount of gas used, x (in gallons), is paired with the distance traveled, y (in miles), for various trips. The equation for the line of best fit for the data is y = 28x. How can the y-intercept and slope of this line be interpreted
Answer:
The answer can be interpreted by the distance moved by each gallon :))
Step-by-step explanation:
Answer:
D.
Step-by-step explanation:
Just took it. Edg 2020. Hope this helps :)
PLEASE HELP the vertex form of the equation of a parabola is y = (x - 3)2 + 36. what is the standard form of the equation?
Answer:
[tex]\large \boxed{\sf \bf \ \ x^2-6x+45 \ \ }[/tex]
Step-by-step explanation:
Hello, please consider the following.
You need to develop the expression.
[tex]y=(x-3)^2+36\\\\=x^2-2 * 3 * x +3^2+36\\\\=x^2-6x+9+36\\\\=x^2-6x+45[/tex]
Thank you.
Answer:
D
Step-by-step explanation:
How to do this question plz answer me step by step plzz plz plz plz plz plz plz plz
Answer:
288.4m
Step-by-step explanation:
This track is split into a rectangle and two semi-circles.
We can find the length of the semi-circles by finding its circumference with the formula [tex]2\pi r[/tex].
[tex]2\cdot3.14\cdot30\\188.4[/tex]
However this is half a circle, so:
[tex]188.4\div2=94.2[/tex].
There are two semi-circles.
[tex]94.2\cdot2=188.4[/tex]
Since there are two legs of 50m each, we add 100 to 188.4
[tex]188.4+100=288.4[/tex]m
Hope this helped!
Answer:
Step-by-step explanation:
To solve for the perimeter, we first look at the rectangle in the middle. the length is 50m, and there are two sides to it, so: 50 * 2 = 100m for the top and bottom of the track.
For the circle, we can see the diameter is 30m. To solve for the circumference, we need to use the formula 2πr.
15 * 2π ≈ 94.2477796077
We add that to 100m and get:
194.2477796077
Please help,thanks!(:
Answer:
<4=<2
x+30=2x+15
x=15
therefore <4=(15)+30
=45°
THIS IS THE HARDEST WORK ON EART SOMEONE HELP ME
Answer:
a) 2 h 45 min
b) 2 h 50 min
c) 2 h 20 min
d) 3 h 20 min
Step-by-step explanation:
Answer:
a) hours: 9 hours 15 minutes
minutes: 555
b) hours: 9hours 10 minutes
minutes: 550
c) hours: 2hours 20 minutes
minutes: 140
d) hours: 3 hours 20 minutes
minutes: 200
Step-by-step explanation:
Given quadrilateral MATH is similar to quadrilateral ROKS calculate the value of MH Picture is below
=====================================================
Explanation:
The double tickmarks for quadrilateral MATH show that MA = TH. Since TH is 5 units long, this makes MA the same length as well.
For quadrilateral ROKS, we have RO = 15. For "MATH" and "ROKS" we have "MA" and "RO" as the first two letters of each four-letter sequence; meaning that MA and RO correspond together.
The ratio of the corresponding segments is RO/MA = 15/5 = 3.
The larger quadrilateral has each side length 3 times longer than the smaller quadrilateral's corresponding side lengths.
--------------
In short,
larger side = 3*(smaller side)
--------------
Using this scale factor of 3, we can find MH
larger side = 3*(smaller side)
RS = 3*(MH)
21 = 3*MH
3*MH = 21
MH = 21/3
MH = 7
please help!! due soon!
Use the graph to complete the statement. O is the origin. T ο r(180°,O) : (4,2)
A. (-5, 0) B. (3, 4) C. (-3, -4) D. ( -4, -2)
Answer: D. (-4, -2)
Step-by-step explanation:
Rotating 180° about the origin means the signs for the x- and y-values are opposite.
(x, y) → (-x, -y)
(4, 2) → (-4, -2)
The coordinate after 180° of rotation will be (-4, -2). Then the correct option is D.
What is a transformation of a point?A spatial transformation is each mapping of feature space to itself and it maintains some spatial correlation between figures.
The line is y = mx, then the point (4, 2).
The point (4, 2) is in the first quadrat.
The line is rotated by 180° about the origin.
Then the coordinate will lies in the third quadrant.
Then the value of the abscissa and ordinate will be transformed into negative.
Then the coordinate after 180° of rotation will be (-4, -2).
Then the correct option is D.
More about the transformation of a point link is given below.
https://brainly.com/question/27224339
#SPJ5
3.03 times 10^-3 in scientific nation
Answer:
3.03 • 10⁻³ is scientific notation
0.00303 is decimal form
La fuerza necesaria para evitar que un auto derrape en una curva varía inversamente al radio de la curva y conjuntamente con el peso del auto y el cuadrado de la velocidad del mismo. Supongamos que 400 libras de fuerza evitan que un auto que pesa 1600 libras derrape en una curva cuyo radio mide 800 si viaja a 50mph. ¿Cuánta fuerza evitaría que el mismo auto derrapara en una curva cuyo radio mide 600 si viaja a 60mph ?
Answer:
768 libras de fuerza
Step-by-step explanation:
Tenemos que encontrar la ecuación que los relacione.
F = Fuerza necesaria para evitar que el automóvil patine
r = radio de la curva
w = peso del coche
s = velocidad de los coches
En la pregunta se nos dice:
La fuerza requerida para evitar que un automóvil patine alrededor de una curva varía inversamente con el radio de la curva.
F ∝ 1 / r
Y luego con el peso del auto
F ∝ w
Y el cuadrado de la velocidad del coche
F ∝ s²
Combinando las tres variaciones juntas,
F ∝ 1 / r ∝ w ∝ s²
k = constante de proporcionalidad, por tanto:
F = k × w × s² / r
F = kws² / r
Paso 1
Encuentra k
En la pregunta, se nos dice:
Suponga que 400 libras de fuerza evitan que un automóvil de 1600 libras patine alrededor de una curva con un radio de 800 si viaja a 50 mph.
F = 400 libras
w = 1600 libras
r = 800
s = 50 mph
Tenga en cuenta que desde el
F = kws² / r
400 = k × 1600 × 50² / 800
400 = k × 5000
k = 400/5000
k = 2/25
Paso 2
¿Cuánta fuerza evitaría que el mismo automóvil patinara en una curva con un radio de 600 si viaja a 60 mph?
F = ?? libras
w = ya que es el mismo carro = 1600 libras
r = 600
s = 60 mph
F = kws² / r
k = 2/25
F = 2/25 × 1600 × 60² / 600
F = 768 libras
Por lo tanto, la cantidad de fuerza que evitaría que el mismo automóvil patine en una curva con un radio de 600 si viaja a 60 mph es de 768 libras.
what is the coefficient of the variable in the expression 4-3x
As per the question,
We have to find what's the coefficient.
Let's start to seperate the expression.
Here,
x is the variable,
4 is a number.
-3 is also a number.
4, -3x
The number with x here is -3 in (-3x) as the coefficient is (-3) in the given equation.
Answer:
Hey there!
Rearrange the expression to: -3x+4
The coefficient would be -3.
Let me know if this helps :)
HELP ASAP
[tex]Given that $33^{-1} \equiv 77 \pmod{508}$, find $11^{-1} \pmod{508}$ as a residue modulo 508. (Give an answer between 0 and 507, inclusive.)[/tex]
===================================================
Work Shown:
[tex]33^{-1} \equiv 77 \text{ (mod 508)}\\\\(3*11)^{-1} \equiv 77 \text{ (mod 508)}\\\\3^{-1}*11^{-1} \equiv 77 \text{ (mod 508)}\\\\3*3^{-1}*11^{-1} \equiv 3*77 \text{ (mod 508)}\\\\11^{-1} \equiv 231 \text{ (mod 508)}\\\\[/tex]
Notice how 33*77 = 2541 and 11*231 = 2541
[tex]2541 \equiv 1 \text{ (mod 508)}[/tex] since 2541/508 has a remainder of 1.
So effectively [tex]33*77 \equiv 1 \text{ (mod 508)}[/tex] and [tex]11*231 \equiv 1 \text{ (mod 508)}[/tex]