Question

(sin theta+cos theta) ^2 + ( sin theta - cos theta) ^2 evaluate​

Answer 1

Step-by-step explanation:

(sin Q+cosQ) ^2 + ( sinQ - cosQ)^2

open the bracket with the help of Identity

(a+b)^2 = a^2+b^2+2ab

= sin^2Q+cos^2 Q+2sinQcosQ+ sin^2Q+cos^2 Q-2sinQcosQ

= sin^2Q+cos^2 Q+sin^2Q+cos^2 Q

= 2sin^2Q+2cos^2 Q

= 2(sin^2Q+cos^2 Q)

= 2. (::sin^2Q+cos^2 Q =1)