SOLUTION: If sin(theta)=1/2 and tan(theta) is less than 0, find cos(theta).

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Question 938450: If sin(theta)=1/2 and tan(theta) is less than 0, find cos(theta).
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Sine is positive, tangent is negative, so cosine must be negative.
%281%2F2%29%5E2%2Bcos%28theta%29%5E2=1
cos%28theta%29%5E2=1-1%2F4
cos%28theta%29%5E2=3%2F4
cos%28theta%29=0+%2B-+sqrt%283%29%2F2
From above,
cos%28theta%29=-sqrt%283%29%2F2