Question

ples help me to solve

Answer 1

Note: Here, I am writing theta as A.

Given, cosA + sinA = 1.

On squaring both sides, we get

= > (cosA + sinA)^2 = (1)^2

= > cos^2A + sin^2A + 2sinAcosA = 1

We know that cos^2A + sin^2A = 1.

= > 1 + 2sinAcosA = 1

= > 2sinAcosA = 0

= > sinAcosA = 0.


Now,

= > (cosA - sinA)^2 = (cos^2A + sin^2A - 2sinAcosA)

                                = (cos^2A + sin^2A + 2sinAcosA) - 4sinAcosA

                                = (cosA + sinA)^2 - 4sinAcosA

                                = (1)^2 - 4(0)

                                = 1 - 0

                                = 1.


= > cosA - sinA = +1, -1.



Hope this helps!