What is the perimeter of the inside of the track?use 3.14 for pie

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

2 years ago

A small town had a population of 960 people last year. The population increased to 1200 people this year. By what percentage did

Licemer1 [7]

Answer:

25%

Step-by-step explanation:

25% of 960 is 240. to find that we need to do...

0.25 x 960 = 240

add the percent increace to the 960.....

960 + 240 = 1,200

Hope this helped! Please mark as brainliest! Thanks!!

8 0

3 years ago

Calculate the mass of NaOH in 0.2 moles of NaOH

masya89 [10]

Answer:

0.2M i.e

Step-by-step explanation:

6 0

3 years ago

How do i calculate the percentage difference between two numbers????

lawyer [7]

When finding the percent difference between two numbers, there are two ways you can do this.

1. The first way is how to calculate the percentage INCREASE of two numbers:

-The formula is Increase / Original Number × 100 = % increase

Step 1: Find out the difference between the two numbers you're comparing. New number - Original number = Increase.

Step 2: Divide the increase by the original number and then multiply your answer by 100. (If your answer is a negative number, then it is a percent decrease, not a percent increase.)

2. The second way is how to calculate the percentage DECREASE of two numbers:

Step 1: Find out the difference between the two numbers you're comparing. Original number - New number = Decrease.

Step 2: Divide the decrease by the original number and then multiply your answer by 100. Decrease ÷ Original Number × 100 = % Decrease. (If your answer is a negative number, then is is a percent increase, not a percent decrease.)

8 0

3 years ago

3x + 8 < 4(x - 3)Solve the inequality and graph the solution set.

solmaris [256]

Step-by-step explanation:

3x+8<4x−12

Move all terms containing x

to the left side of the inequality.

Tap for more steps...

−x+8<−12

Move all terms not containing x

−x<−20

x>20

Interval Notation:(20,∞)

7 0

3 years ago