Question

Cos^2x-2sinxcosx-sin^2x=1 solve

Answer 1

Step-by-step explanation:

cos²x-2sinxcosx-sin²x= 1

LHS

=> (cos²x-sin²x)-2sinxcosx

=> cos2x-sin2x

iff 2x= 0 or 270°

=> cos2x - sin 2x= 1

=> x= 0 or x= 135°

only the two situations LHS = 1 other wise≠1