Question

prove that sin 2x=2sinx.cosx​

Answer 1

Step-by-step explanation:

Assume that sin(2x) = sin(x + x)

From trigonometry,

sin(a + b) = sin(a)cos(b) + cos(a)sin(b)

Similarly,

sin(x + x) = sin(x)cos(x) + cos(x)sin(x),

sin(x + x) = sin(x)cos(x) + sin(x)cos(x)

therefore,

sin(x + x) = sin(2x) = 2sin(x)cos(x