How do you solve cosx=sinxcosx=sinx and find all exact general solutions?

1 Answer
Jul 22, 2016

x = pi/4 + 2kpix=π4+2kπ

Explanation:

cos x = sin x
Property of complementary arcs -->
cos x = sin (pi/2 - x)cosx=sin(π2x)
There for:
sin x = sin (pi/2 - x)
There are 2 solutions:
a. x = pi/2 - xx=π2x --> 2x = pi/22x=π2 --> x = pi/4x=π4
b. x = pi - (pi/2 - x) = pi/2 + xx=π(π2x)=π2+x
Undefined equation .
General answer:
x = pi/4 + 2kpix=π4+2kπ