Solve without using a calculator

[Jasonrich]

Hi, this is my first post, so sorry for anything I do wrong

I have gotten a previous math exam to do for homework and I'm having trouble figuring out what to do
Given: a diagram that has an angle x, a point P(-3;4) that is extended to the origin
I need to, without using a calculator, find the numeric value of: (sinx)/(1 + cos2x)
The angle x is toward the right of the PO line. I've no clue what to do after finding the value of x, which I found to be 126,87 degrees.

Any help will be much appreciated

I said the angle was 'x' because I don't have(know how to get) that symbol on my keyboard

 

[DrPhil]

Hi, this is my first post, so sorry for anything I do wrong

I have gotten a previous math exam to do for homework and I'm having trouble figuring out what to do
Given: a diagram that has an angle x, a point P(-3;4) that is extended to the origin
I need to, without using a calculator, find the numeric value of: (sinx)/(1 + cos2x)
The angle x is toward the right of the PO line. I've no clue what to do after finding the value of x, which I found to be 126,87 degrees.

Any help will be much appreciated

I said the angle was 'x' because I don't have(know how to get) that symbol on my keyboard
View attachment 2877

WITHOUT A CALCULATOR, how did you possibly get that measure in degrees? Note that the question did not ask for \alpha, just functions of \alpha.

Start with what you know. If x = -3 and y = +4, what is the hypotenuse?
Once you know the hypotenuse, what are sin(\alpha) and cos(\alpha)?
What is the double-angle formula for cosine?

edit - can't use "x" for both the angle and the coordinate .. switched name of angle to \alpha

 

[Jasonrich]

WITHOUT A CALCULATOR, how did you possibly get that measure in degrees? Note that the question did not ask for \alpha, just functions of \alpha.

Start with what you know. If x = -3 and y = +4, what is the hypotenuse?
Once you know the hypotenuse, what are sin(\alpha) and cos(\alpha)?
What is the double-angle formula for cosine?

edit - can't use "x" for both the angle and the coordinate .. switched name of angle to \alpha

Okay thanks a lot!
I just wasn't sure what to do, but now i get it, thanks