Question

(sin theta+ cos theta)2 + (sin theta - cos theta)?​

Answer 1

Answer:

Answer is 2.

Step-by-step explanation:

(sin∅ + cos∅)² + (sin∅ - cos∅)² [Since (sin∅ + cos∅)²=(a+b)² = a² + 2ab + b² and. (sin∅ - cos∅)²= (a-b)² = a²-2ab+b²]

=sin²∅+2sin∅cos∅+cos²∅+sin²∅-2sin∅cos∅+cos²∅

= sin²∅ + cos²∅ + sin²∅ + cos²∅

(Since +2sin∅.cos∅ and -2sin∅.cos∅ are cancel)

= 1 + 1 (sin²∅ + cos²∅ = 1 Identity)

= 2

:. (sin∅ + cos∅)² + (sin∅ - cos∅)² = 2