Question

At x= pi/4 , find the product (sin4x)(cos5x)

Answer 1

• zero

Explanation:

x= π/4

• sin(4x)*cos(5x) =
• sin(4*π/4)*cos (5*π/4) =
• sin(π)*cos(5π/4)

sin(π) = 0, therefore the product is also zero