How do you prove $sin(pi/4 + x) = cos (pi/4 - x)$ ?

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Answer 1 · 2016-03-23T05:48:27

Expand the terms and use the identity $sin^2(x) + cos^2(x) = 1$

sin(π/4) + sin x = cos(π/4) − cos x)

sin x = 1 − cos x
sin(x) + cos(x) = 1

$sin^2(x) + cos^2(x) = 1$

How do you prove sin(pi/4 + x) = cos (pi/4 - x)sin(pi/4 + x) = cos (pi/4 - x)?