SOLUTION: Jenny needs to find sin2x, and she knows that 0 < x < &#960;. She also knows that sin2x and cosx are 7/25 and 24/25, but she doesn't know which is which. a) why isn't it necessary

Algebra ->  Trigonometry-basics -> SOLUTION: Jenny needs to find sin2x, and she knows that 0 < x < &#960;. She also knows that sin2x and cosx are 7/25 and 24/25, but she doesn't know which is which. a) why isn't it necessary      Log On


   

Question 1031264: Jenny needs to find sin2x, and she knows that 0 < x < π. She also knows that sin2x and cosx are 7/25 and 24/25, but she doesn't know which is which.
a) why isn't it necessary for her to distinguish between the two?
b) Find the value of sin2x for both cases
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Do you mean sin 2x, or sin^2 x?

Also, if cos x = 24/25, then sin x = 7/25 (since 0 < x < pi, so sin x is positive, and using the fact that sin^2 x + cos^2 x = 1), and it is impossible for sin 2x or sin^2 x to also equal 7/25. Same thing if cos x = 7/25.