SOLUTION: If sin(θ)= 4/7 and tan(θ)>0, find cos(θ)

Algebra ->  Trigonometry-basics -> SOLUTION: If sin(θ)= 4/7 and tan(θ)>0, find cos(θ)      Log On


   

Question 1018459: If sin(θ)= 4/7 and tan(θ)>0, find cos(θ)
Answer by ikleyn(52908) About Me  (Show Source):
You can put this solution on YOUR website!
.
If sin(θ)= 4/7 and tan(θ)>0, find cos(θ)
---------------------------------------------------------- 

cos%28theta%29 = sqrt%281-sin%5E2%28theta%29%29 = sqrt%281+-+%284%2F7%29%5E2%29 = sqrt%281+-+16%2F49%29 = sqrt%28%2849-16%29%2F49%29 = sqrt%2833%2F49%29 = sqrt%2833%29%2F7.


The sign of the square root is chosen "+" since sin%28theta%29 > 0 and tan%28theta%29 > 0.