求定积分 ∫[-2,1] 1/(11+5x)^3dx

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求定积分 ∫[-2,1] 1/(11+5x)^3dx

求定积分 ∫[-2,1] 1/(11+5x)^3dx
求定积分 ∫[-2,1] 1/(11+5x)^3dx

求定积分 ∫[-2,1] 1/(11+5x)^3dx
∫[-2,1] 1/(11+5x)^3dx
=1/5∫[-2,1] (11+5x)^(-3)d(11+5x)
=1/5*(11+5x)^(-3+1)/(-3+1)[-2,1]
=-1/[10(11+5x)^2][-2,1]
=-[1/2560-1/10]
=51/512

∫[-2, 1] 1/(11+5x)³ dx
=(1/5)∫[-2, 1] 1/(11+5x)³ d(5x+11)
=(1/5)∫[1, 16] 1/t³ dt
=-(1/10) 1/t² |[1, 16]
=-(1/10)(1/16²-1)
=255/2560
=51/512