Question

How do you use the half angle formula to prove `(Cos (θ/2) - Sin( θ/2))^2`?

Answer 1

`(cos(theta/2)-sin(theta/2))^2=1+sintheta`

Explanation:

It appears as if something has been left in the question as there is no equation in the question.

However, we are using the formulas `sinA=2sin(A/2)cos(A/2)` and `sin^2A+cos^2A=1` and arriving at a likely result.

`(cos(theta/2)-sin(theta/2))^2`

= `cos^2(theta/2)+sin^2(theta/2)+2cos(theta/2)sin(theta/2)`

= `1+sintheta`

Hope it helps.