If the dimensions of a triangle are cut in half, then the new perimeter is one fourth of the original perimeter. TrueFalse

For 0 ≤ ϴ < 2π, how many solutions are there to tan(StartFraction theta Over 2 EndFraction) = sin(ϴ)? Note: Do not include va

Black_prince [1.1K]

Answer:

3 solutions:

$\theta={0, \frac{\pi}{2}, \frac{3\pi}{2}}$

Step-by-step explanation:

So, first of all, we need to figure the angles that cannot be included in our answers out. The only function in the equation that isn't defined for some angles is $tan(\frac{\theta}{2})$ so let's focus on that part of the equation first.

We know that:

$tan(\frac{\theta}{2})=\frac{sin(\frac{\theta}{2})}{cos(\frac{\theta}{2})}$

therefore:

$cos(\frac{\theta}{2})\neq0$

so we need to find the angles that will make the cos function equal to zero. So we get:

$cos(\frac{\theta}{2})=0$

$\frac{\theta}{2}=cos^{-1}(0)$

$\frac{\theta}{2}=\frac{\pi}{2}+\pi n$

or

$\theta=\pi+2\pi n$

we can now start plugging values in for n:

$\theta=\pi+2\pi (0)=\pi$

if we plugged any value greater than 0, we would end up with an angle that is greater than $2\pi$ so, that's the only angle we cannot include in our answer set, so:

$\theta\neq \pi$

having said this, we can now start solving the equation:

$tan(\frac{\theta}{2})=sin(\theta)$

we can start solving this equation by using the half angle formula, such a formula tells us the following:

$tan(\frac{\theta}{2})=\frac{1-cos(\theta)}{sin(\theta)}$

so we can substitute it into our equation:

$\frac{1-cos(\theta)}{sin(\theta)}=sin(\theta)$

we can now multiply both sides of the equation by $sin(\theta)$

so we get:

$1-cos(\theta)=sin^{2}(\theta)$

we can use the pythagorean identity to rewrite $sin^{2}(\theta)$ in terms of cos:

$sin^{2}(\theta)=1-cos^{2}(\theta)$

so we get:

$1-cos(\theta)=1-cos^{2}(\theta)$

we can subtract a 1 from both sides of the equation so we end up with:

$-cos(\theta)=-cos^{2}(\theta)$

and we can now add $cos^{2}(\theta)$

to both sides of the equation so we get:

$cos^{2}(\theta)-cos(\theta)=0$

and we can solve this equation by factoring. We can factor $cos(\theta)$ to get:

$cos(\theta)(cos(\theta)-1)=0$

and we can use the zero product property to solve this, so we get two equations:

Equation 1:

$cos(\theta)=0$

$\theta=cos^{-1}(0)$

$\theta={\frac{\pi}{2}, \frac{3\pi}{2}}$

Equation 2:

$cos(\theta)-1=0$

we add a 1 to both sides of the equation so we get:

$cos(\theta)=1$

$\theta=cos^{-1}(1)$

$\theta=0$

so we end up with three answers to this equation:

$\theta={0, \frac{\pi}{2}, \frac{3\pi}{2}}$

7 0

3 years ago

- 4. What is the roster form of the set K = {x/x are odd numbers from 2 to 8} ? A. H = {2, 4, 6, 8} C. H = {3, 4, 5, 6, 7} B. H

tangare [24]

<h3>Answer: H = {3, 5, 7}</h3>

Explanation:

We simply list any odd number that is between 2 and 8. The term "roster form" can be thought of as listing the roster of a sports team (eg: baseball). So instead of describing what the numbers look like, we list out the numbers themselves. Those numbers being 3, 5 and 7.

Something like {2,4,6,8} is ruled out because we're dealing with odd numbers only.

3 0

3 years ago

How much money would I need to invest for six years at 4 1/2 percent Simple interest to earn $400?

lbvjy [14]

Answer: 1481.48

Step-by-step explanation:

SI = prt

400 = p x 0.045 x 6

400 = 0.27p

P = 400 / 0.27

P = 1481.48

6 0

3 years ago

Please help thanks :)

kykrilka [37]

Question 1:

Multiply both sides of the proportion by 35.

You get.

7(x-1) = 4x+2

7x-7 = 4x+2

Now, add both sides by 7 and subtract both sides by 4x

3x = 9

Divide both sides by 3

x=3

Question 2:

Multiply both the numerator and the denominator of $\frac{x+1}{x+3}$ by 3.

We want to multiply it by 3 so that the +1 and +3 become +3 and +9. +3 and +9 have a difference of 6, just like 15 and 21, which is what we want.

$\frac{3x+3}{3x+9} = \frac{15}{21}$

Set the numerator equal to the numerator and the denominator equal to the denominator.

3x+3 = 15

3x+9 = 21

If you solve both of these, you get x=4 for both.

That's your answer.

Hope this helps! :)

8 0

3 years ago

Find the translation rule and the scale factor of the dilation that transforms Ol to Ol'.

lisov135 [29]

Answer:

C (x, y) -> (x + 7, y + 8); scale factor = 3

Step-by-step explanation:

The translation can be found by subtracting the coordinates of the original center from those of the center of the image. The scale factor will be the ratio of the radii.

__

<h3>translation</h3>

We note the center coordinates are I(-3, -6) and I'(4, 2). Then the translation is ...

I' -I = (4, 2) -(-3, -6) = (4 +3, 2 +6) = (7, 8)

(x, y) ⇒ (x +7, y +8)

<h3>scale factor</h3>

The radius of each circle can be found by counting the grid squares from the center to the circle. It works best to do this along a horizontal or vertical line.

The radius of circle I is 2; the radius of circle I' is 6. The scale factor is ...

scale factor = 6/2 = 3

4 0

2 years ago