Question

No 5 how do we do with explanation there is answer but how the
that comes

Answer 1

see explanation

Explanation:

(sinA + cosA)² + (sinA - cosA)² ← expand using FOIL

= sin²A + 2sinAcosA + cos²A + sin²A - 2sinAcosA + cos²A ← collect like terms

= 2sin²A + 2cos²A

Answer 2

I don't understand what is your question?