不定积分∫sin (3-5x) dx

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不定积分∫sin (3-5x) dx

不定积分∫sin (3-5x) dx
不定积分∫sin (3-5x) dx

不定积分∫sin (3-5x) dx
-cos(3-5x)+C

F =

cos(3 - 5*x)/5+C

Method 1 :换元积分法
令u = 3-5x,du = -5dx -> dx = (-1/5)du
原式 = ∫ sinu * (-1/5)du
= (-1/5) * (-cosu) + c
= (1/5)cos(3-5x) + c
Method 2:凑微分法
∫ sin(3-5x) dx
= ∫ sin(3-5x) d(-5x) / ...

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Method 1 :换元积分法
令u = 3-5x,du = -5dx -> dx = (-1/5)du
原式 = ∫ sinu * (-1/5)du
= (-1/5) * (-cosu) + c
= (1/5)cos(3-5x) + c
Method 2:凑微分法
∫ sin(3-5x) dx
= ∫ sin(3-5x) d(-5x) / (-5),先凑个-5,乘以-5再除以-5
= (-1/5)∫ sin(3-5x) d(-5x)
= (-1/5)∫ sin(3-5x) d(-5x+3),再凑个+3
= (-1/5)∫ sin(3-5x) d(3-5x)
= (-1/5) * [-cos(3-5x)] + c
= (1/5)cos(3-5x) + c

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