Derive a formula for sin (2?) in terms of sin (?) and cos (?) for all real numbers?.

Answer: sin (2α) = 2 sin (α) cos (α)

Step-by-step explanation:

We departure from the sin of a sum of angles

sin (α + β) = sinα * cosβ + sinβ * cosα

if α = β ⇒ sin (α + α) = sin (α) * cos (α) + sin (α) * cos (α)

sin (2α) = 2 sin (α) cos (α)