## aussy123 2 years ago How do I solve this problem? Solve for cosθ in sin^2θ + cos^2θ = 1

1. terenzreignz

This? $\large \sin^2\theta+\cos^2\theta=1$

2. aussy123

yes

3. terenzreignz

Well, let's see... How to break this to you... cosθ can literally be any value from [-1 , 1] Let me explain... the value of cosθ depends on the value of θ, right?

4. aussy123

yes

5. terenzreignz

Well, unfortunately (fortunately?) ANY value of θ would make this statement true sin²θ + cos²θ = 1

6. hartnn

he/she needs to solve for cos so, subtract sin^2 term from both sides, what u get ?

7. terenzreignz

Oops... Must have been overexcited :) My bad

8. aussy123

Im trying to write it but its giving me a hard time

9. aussy123

±√(1 + sin2Θ)

10. hartnn

did you mean $$\pm \sqrt{1-\sin^2 \theta}$$ ??

11. aussy123

yes I pasted the wrong one Sorry, my computer is acting really crazy today

12. hartnn

ohh..if you meant that, then you are correct.

13. aussy123

ok thanks you made this very easy, thank you.. :)

14. hartnn

glad to hear :) welcome ^_^