look up your formulas. You want
2 sin(a) cos(b) = sin(a+b) cos(a-b)
You don't even need the product-to-sum formulas, since your double-angle formula says that
cos(2x) = 2 sinx cosx
Use the product-to-sum formula to write the given product as a sum or difference.
6sin π/10 cos π/ 10
4 answers
Dang! That is
sin(2x) = 2 sinx cosx
sin(2x) = 2 sinx cosx
that isn't one of my answers?
you telling me or asking me?
Naturally, sin(2x) is not one of your answers, but if you let x = π/10 and you plug that in, I bet it is one of your answers.
Naturally, sin(2x) is not one of your answers, but if you let x = π/10 and you plug that in, I bet it is one of your answers.