(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

cos^-1(sin(5pi/4))

2. Relevant equations

n/a

3. The attempt at a solution

I began by finding the reference angle of 5pi/4 by subtracting pi, and I got pi/4. pi/4 must be part of an isosceles right triangle, so I drew a diagram with sides 1,1, and √2. I found sin pi/4 to equal 1/√2, which I rationalized and got √2/2. I viewed my cosine chart, and cosine is √2/2 where the angle is pi/4. I answered pi/4 into MyMathLab, which found it incorrect, so I concluded that I am most likely doing it wrong.

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# Homework Help: Find exact value of composite trig function.

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