Integral dari 4 ( sin 7X . Cos 5x ) dx

Integral Fungsi Trigonometri.

sin α cos β = 1/2 [sin (α + β) + sin (α - β)]

∫ 4 sin 7x cos 5x dx
= 4 ∫ [1/2 sin (7x + 5x) + sin (7x - 5x)] dx
= 2 ∫ (sin 12x + sin 2x) dx
= 2 (-1/12 cos 12x - 1/2 cos 2x) + C
= -1/6 (cos 12x + 6 cos 2x) + C