Question

prove that 4sinΠ/10 sin13Π/10=-1​

Answer 1

Answer:

HI MATE

THE ANSWER OF THIS QUESTION IS

Step-by-step explanation:

sin π/10 + sin 13π/10

= sin π/10 - sin 3π/10

= 2 cos 2π/10 sin (-π/10)

= - 2[(sqrt5 + 1)/4][sqrt5 - 1)/4]

= -2*(5 -- 1)/16

= -1/2