Question

Express in the form A sin(x + c)

sin x − cos x

Answer 1

\[\sqrt{2} \sin(x - \frac{ \pi }{4 })\]
is the solution.
Not sure how it is done.
Assuming there is an identity I can't remember

Answer 2

let's begin this problem by expanding the left side using the formula for the sine of a sum of angles:

Answer 3

Are you ok with the expression appearing between the [ ] ?