问题标题:
若函数f(x)=1,(x≤√3)√(4-x^2),(√3<x<2)0,(x≥2)则∫2,-1[f(x)+x]dx的值为
问题描述:
若函数f(x)=1,(x≤√3)√(4-x^2),(√3<x<2)0,(x≥2)则∫2,-1[f(x)+x]dx的值为
龚跃玲回答:
∫[f(x)+x]dx=∫(1+x)dx+∫[√(4-x²)+x]dx
=√3+√3²/2+1-1/2+2²/2-√3²/2+∫√(4-x²)dx
=√3+5/2+∫4cos²tdt(令x=2sint)
=√3+5/2+2∫[1+cos(2t)]dt
=√3+5/2+2(π/2-π/3)+sin(π)-sin(2π/3)
=√3+5/2+π/3-√3/2
=√3/2+5/2+π/3.
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