SOLUTION: How do I express cos(theta) in terms of sin(theta)? I'm taking an online pre-cal course without a teacher, and I don't understand how to solve this. I do know that {{{ sin^2(the

Algebra ->  Trigonometry-basics -> SOLUTION: How do I express cos(theta) in terms of sin(theta)? I'm taking an online pre-cal course without a teacher, and I don't understand how to solve this. I do know that {{{ sin^2(the      Log On


   

Question 1005478: How do I express cos(theta) in terms of sin(theta)?
I'm taking an online pre-cal course without a teacher, and I don't understand how to solve this. I do know that +sin%5E2%28theta%29+%2B+cos%5E2%28theta%29+=+1+.
Would this mean that +cos%28theta%29+=+sqrt%281-sin%5E2%28theta%29%29+?
Thanks in advance!
Answer by josgarithmetic(39620) About Me  (Show Source):
You can put this solution on YOUR website!
Same algebra concepts and skills from your earlier algebra courses. Solve for cosine of theta in terms of sine of theta. What would you do if you had x^2+y^2=k, and you wanted to solve for x in terms of y? And then how do you finish this properly, to account for the square root?

x%5E2%2By%5E2=k
x%5E2%2By%5E2-y%5E2=k-y%5E2
x%5E2%2B0=k-y%5E2
x%5E2=k-y%5E2
x=0%2B-sqrt%28k-y%5E2%29



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The addition of 0 was included to make the rendering on the site work.