Question

if sinx + cosx = 1, then find the value of x.

Answer 1

sinx + cosx = 1

Squaring both sides,

${ \sin }^{2} x + cos^{2} x + 2 \sin(x) \cos(x) = 1$

1 + 2sinxcosx = 1

2sinxcosx = 0

sinxcosx = 0

sinx = 0 or cosx = 0

Therefore

x = 0 or x = 90