Jika f(x) = xcosx, maka f'(x + π/2) =...
Matematika
ardiana991
Pertanyaan
Jika f(x) = xcosx, maka f'(x + π/2) =...
1 Jawaban
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1. Jawaban DB45
Turunan Trigonometri
f(x) = x cos x
u = x --> u' = 1
v = cos x --> v' = - sin x
f = uv --> f' = u'v + uv'
f' (x) = 1(cos x) + (x)(-sin x)
f ' (x) = cos x - x sin x
f ' (x + π/2) = cos (x + π/2) - (x+π/2) sin (x + π/2)
f '(x + π/2) = - sin x - (x + π/2) cos x
f '(x + π/2) = - sin x - x cos x - π/2 cos x