Prove that : cos 3π/13 * cos 5π/13 - cos 8π/13 * cos 10π/13 = 0

the discriminant is 64 + 4*1*12 = 112

this is prime.

step-by-step explanation:

answer: give more info

step-by-step explanation:

for this pair of functions g(x)=x-2 and f(x)=|x| is (g o f)(a)= |a| -2

step-by-step explanation:

g(x)=x-2

f(x)=|x|

(g o f)(a)=?

(g o f)(x)=g(f(x))

(g o f)(x)=g(|x|)

(g o f)(x)=|x|-2

(g o f)(a)=|a|-2