Which sum or difference identity could be used to prove that sin (pi+q) = -sinq

see explanation

Step-by-step explanation:

Using the Addition formula for sine

sin (x + y) = sinxcosy + cosxsiny

and sinπ = 0, cosπ = - 1, then

sin (π + q)

= sinπcosq + cosπsinq

= 0. cosq + ( - 1) sinq

= 0 - sinq

= - sinq ← as required