Question

If k = sinx + cosx and a = sinx - cosx then $k^2$ + $a^2$ is independent of x

• A. True
• B. False

Answer 1

The correct option is A

True

$k^2$ + $a^2$ = $(sinx+cosx{)}^2$ + $(sinx-cosx{)}^2$

= 1 + 2sinxcosx + 1-2sinxcosx

= 2

This is independent of x.

$\Rightarrow$ True.