Question

If sina - cosa = 1, prove that sina + cosa = +_1

please prove it in detail​

Answer 1

Step-by-step explanation:

The explanation is in above picture

Answer 2

Step-by-step explanation:

sina - cosa = 1

squaring on both sides

(sina - cosa)^2= 1^2

sin^a+cos^2a-2sinacosa=1

1-sin2a=1

sin2a=0 ......(1)

(sina +cosa)^2

=sin^a+cos^2a+2sinacosa

=1+sin2a

=1+0 (from(1))

=1

sina +cosa=+or-1