SOLUTION: If sin θ = 2 over 7 and tan θ > 0, what is the value of cos θ? I have to show work

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Question 1042536: If sin θ = 2 over 7 and tan θ > 0, what is the value of cos θ?
I have to show work
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Use,
cos%5E2%28theta%29%2Bsin%5E2%28theta%29=1
cos%5E2%28theta%29%2B%282%2F7%29%5E2=1
cos%5E2%28theta%29=1-4%2F49
cos%5E2%28theta%29=45%2F49
cos%28theta%29=0+%2B-+%283%2F7%29sqrt%285%29
Since you know that tan%28theta%29=sin%28theta%29%2Fcos%28theta%29%3E0 and sin%28theta%29%3E0, then cos%28theta%29%3E0
So,
cos%28theta%29=%283%2F7%29sqrt%285%29