kak soal integral lagi

Materi integral trigonometri

1•
dcos (3t + π/4) = -3 sin (3t + π/4) dt
sin (3t + π/4) dt = -1/3 dcos (3t + π/4)

∫2sin (3t + π/4) dt [π/3 ... 0]
= 2.(-1/3) ∫dcos (3t + π/4)
= -2/3 cos (3t + π/4)
= -2/3 ( cos (3.π/3 + π/4) - cos (3.0 + π/4))
= -2/3 ( coa (π + 1/4 π) - cos π/4)
= -2/3 ( cos 225° - cos 45°)
= -2/3 (-2 × cos 45°)
= 4/3 × 1/2 √2
= 2/3 √2


2•
dsin (4x - 3) = 4 cos (4x - 3) dx
cos (4x - 2) dx = 1/4 dsin (4x - 3)

∫3 cos (4x - 4) dx [1...0]
= 3 . (1/4) ∫dsin (4x - 3)
= 3/4 sin (4x - 3)
= 3/4 ( sin (4.1 - 3) - sin (4.0 - 3))
= 3/4 (sin 1 - sin (-3))
= 3/4 (sin 1 + sin 3)
= 3/4 (sin (180°/3,14 + sin (3 180°/3,14)
= 3/4 × 0,981
= 0,736