To which set or sets does -20 belong to, whole numbers, rational numbers or integers

Sin theta+costheta/sintheta -costheta+sintheta-costheta/sintheta+costheta=2sec2/tan2 theta -1

sleet_krkn [62]

$\dfrac{sin\theta + cos\theta}{sin\theta-cos\theta}+\dfrac{sin\theta-cos\theta}{sin\theta+cos\theta}=\dfrac{2sec^2\theta}{tan^2\theta-1}$

From Left side:

$\dfrac{sin\theta + cos\theta}{sin\theta-cos\theta}\bigg(\dfrac{sin\theta+cos\theta}{sin\theta+cos\theta}\bigg)+\dfrac{sin\theta-cos\theta}{sin\theta+cos\theta}\bigg(\dfrac{sin\theta-cos\theta}{sin\theta-cos\theta}\bigg)$

$\dfrac{sin^2\theta+2cos\thetasin\theta+cos^2\theta}{sin^2\theta-cos^2\theta}+\dfrac{sin^2\theta-2cos\thetasin\theta+cos^2\theta}{sin^2\theta-cos^2\theta}$

NOTE: sin²θ + cos²θ = 1

$\dfrac{1 + 2cos\theta sin\theta}{sin^2\theta-cos^2\theta}+\dfrac{1-2cos\theta sin\theta}{sin^2\theta-cos^2\theta}$

$\dfrac{1 + 2cos\theta sin\theta+1-2cos\theta sin\theta}{sin^2\theta-cos^2\theta}$

$\dfrac{2}{sin^2\theta-cos^2\theta}$

$\dfrac{2}{\bigg(sin^2\theta-cos^2\theta\bigg)\bigg(\dfrac{cos^2\theta}{cos^2\theta}\bigg)}$

$\dfrac{2sec^2\theta}{\dfrac{sin^2\theta}{cos^2\theta}-\dfrac{cos^2\theta}{cos^2\theta}}$

$\dfrac{2sec^2\theta}{tan^2\theta-1}$

Left side = Right side <em>so proof is complete</em>

8 0

3 years ago

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A student spent 15 minutes getting a 2-foot by 3-foot bulletin board. To the nearest tenth of a minute, how long did it take the

Cerrena [4.2K]

Answer:

The student took 2.5 minutes to paint 1 square foot.

Step-by-step explanation:

In order to know how long the student took to paint each square foot we first need to know the total area of the bulletin board. Since it is a rectangle we can compute it's area by multiplying the width and the height. That is:

area = 2*3 = 6 square foot

Since the student took 15 minutes to paint the whole board the pace at which he was working can be calculated by dividing the total area of the board by the time he took to paint all of it. So we have:

pace = 6/15 = 0.4 foot/min

To find how long it took him to paint 1 square foot we can divide it by the pace he was painting. We have:

time = 1/0.4 = 2.5 minutes

The student took 2.5 minutes to paint 1 square foot.

3 0

3 years ago

Plsssssssssssssssssssssssssssssssssssssssssssssssssssssssssssssss help

Lunna [17]

Answer:

37.68cm

Step-by-step explanation:

C = 2 $\pi$ r

C = circumference

$\pi$ = the constant pi (3.14)

r = radius of the circle (6cm)

d = diameter of the circle (12cm)

d = 2r

C = 2 · 3.14 · 6

C = 37.68cm

8 0

3 years ago

The volume of a cylinder of radius r and height h is given by V = π r 2 h. Then the height, in terms of the radius and volume, i

sdas [7]

Hello There!

It is represented as: h = $\frac{v }{ \pi r^{2} }$

Hope This Helps You!
Good Luck :)

- Hannah ❤

5 0

3 years ago

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X 2x+24<br> Please help me I don’t know what to do

valkas [14]

Answer:

x = 52°

Also, you can use this formula for any other angles. For example, input 90° instead of 180°. I have a feeling that you didn't understand this before. Maybe this will help.

Step-by-step explanation:

180° = x+2x+24°

180° = 3x° + 24°

180° - 24° = 3x

156° = 3x

x = 52°

3 0

2 years ago