Prove that: `s in" "(n" "+" "1)" "x" "s in" "(n" "+" "2)x" "+" "cos" "(n" "+" "1)" "x" "cos" "(n" "+" "2)" "x" "=" "cos" "x`

Prove that: sin (n + 1) x sin (n + 2)x + cos (n + 1) x cos (n + 2) x = cos x

Prove that sin (n+1) x sin (n +2) x + cos (n +1) x cos (n +2) x = cos x

Prove the following: sin (n + 1)x sin (n + 2)x + cos (n + 1)x cos (n + 2)x = cos x

sin (n +1) x sin (n +2) x + cos (n +1) x cos (n +2) x = cos x

sin (n +1) x sin (n +2) x + cos (n +1) x cos (n +2) x = cos x

sin (n +1) x sin (n +2) x + cos (n +1) x cos (n +2) x = cos x

sin (n +1) x sin (n +2) x + cos (n +1) x cos (n +2) x = cos x

Prove that: sin(n+1)x sin(n+2)x+cos(n+1)x cos(n+2)x=c

Prove that (i) cos (n + 2) x cos (n+1) x +sin (n+2) x sin (n+1) x = cos x) (ii) " cos " .((pi)/(4)-x) " cos " .((pi)/(4)-y) " - sin " ((pi)/(4)-x ) " sin " ((pi)/(4) -y) =" sin " (x+y)

Prove that nC_ (1) sin x * cos (n-1) x + nC_ (2) sin2x * cos (n-2) x + nC_ (3) sin3x * cos (n-3) x + ... + nC_ ( n) sin nx = 2 ^ (n-1) sin nn