Question

how 2 come there pls tell tommarow exam​

Answer 1

Answer:

when u expand (a+b)whole square, the identity is a square + b square + 2 (ab) .

So, when (sinA + cosA)2 is expanded, answer wil come as sin2A + cos2A+ 2cosAsinA

I hope you understand.

Answer 2

Answer:

dude it's the formula of (sinA+cosA)-1 you can also see in the examples of book

and it also expended in (a+b)^

(sin^A+cos^A)+2cosAsinA