Are there any solutions for this equation within (0,2π)? [cosx=sinx] if so, what are they?

1 Answer
Apr 18, 2018

x=π4,5π4

Explanation:

Examining the unit circle, we see where cosx=sinx, or where (x,y)=(x,x):

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x=π4,5π4

It does not hold true in the other quadrants (quadrants II, IV), as the sine and cosine have opposite signs for all angles in those quadrants.