# Homework Help: Not your normal Trigonometry Question

1. Feb 7, 2012

### chrisy2012

1. The problem statement, all variables and given/known data

The equation is here:
http://www.wolframalpha.com/input/?i...E2/(.98)
You are trying to solve for the angle in this case x

wolframalpha gave a solution to this problem but it did not show the steps and I can't use that on the test. So can anyone please do the honor of showing me how to get there?

2. Relevant equations
Any identities that has to do with trig

3. The attempt at a solution
I tried using sin^2 = 1 - cos^2 but that doesn't help

2. Feb 7, 2012

3. Feb 7, 2012

### eumyang

First off, the link doesn't work.

Second, is this part of a take-home test? Aren't there rules about getting help for things like this?

4. Feb 7, 2012

### chrisy2012

oops, i swore it worked before
well anyways the equation is this
sin^2(x)/cos(x) = v^2/gR
everything on the right hand side is known and you are solving for x

5. Feb 7, 2012

### chrisy2012

And Don't worry, it's not a take home test, it's one of the problems from mastering physics, I have already gotten the right answer but I want to know how to solve these kind of questions in case it comes up on the test.

6. Feb 7, 2012

### thepatient

Try using trigonometric identity cos^2(x) = 1 - sin^2(x), and move all the cosines on one side and setting equal to zero.

7. Feb 8, 2012

### chrisy2012

I already tried that, it did not work, you have to know the value of cos(x) in order to solve it that way

8. Feb 8, 2012

### Dickfore

lol.

Can you solve this equation:
$$\frac{1}{z} - z = a$$
with respect to z.

9. Feb 8, 2012

### chrisy2012

you have to multiply by "Z" and use quadratic formula?

10. Feb 8, 2012

### Dickfore

So, what's the solution?

11. Feb 8, 2012

### chrisy2012

oh got it, haha thanks, it was easier than i thought

12. Feb 8, 2012

### Dickfore

good for you.