设f(x)=∫(1~√x)e^[-(t^2)dt,求∫(0~1)f(x)/√xdx,答案是e^(-1)-1,

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设f(x)=∫(1~√x)e^[-(t^2)dt,求∫(0~1)f(x)/√xdx,答案是e^(-1)-1,
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设f(x)=∫(1~√x)e^[-(t^2)dt,求∫(0~1)f(x)/√xdx,答案是e^(-1)-1,
设f(x)=∫(1~√x)e^[-(t^2)dt,求∫(0~1)f(x)/√xdx,答案是e^(-1)-1,

设f(x)=∫(1~√x)e^[-(t^2)dt,求∫(0~1)f(x)/√xdx,答案是e^(-1)-1,
由微积分基本定理求导得f'(x)=0.5e^(-x)/根号(x),且f(1)=1.求积分时先用分部积分就可以了.
原积分=2积分(从0到1)f(x)d(根号(x))=
2根号(x)*f(x)|上限1下限0-2积分(从0到1)根号(x)*f‘(x)dx
=-积分(从0到1)e^(-x)dx
=e^(-x)|上限1下限0
=e^(-1)-0.

f(x) = ∫(1→√x) e^(-t²) dt
f'(x) = e^[-(√x)²] • d/dx √x
= e^(-x) * 1/(2√x)
f(1) = ∫(1→1) e^(-t²) dt = 0
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f(x) = ∫(1→√x) e^(-t²) dt
f'(x) = e^[-(√x)²] • d/dx √x
= e^(-x) * 1/(2√x)
f(1) = ∫(1→1) e^(-t²) dt = 0
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∫(0→1) f(x)/√x dx
= 2∫(0→1) f(x) d√x
= 2√xf(x)|(0→1) - 2∫(0→1) √xf'(x) dx
= [2f(1) - 0] - 2∫(0→1) √x • [e^(-x) • 1/(2√x)] dx
= -∫(0→1) e^(-x) dx
= ∫(0→1) e^(-x) d(-x)
= e^(-x)|(0→1)
= e^(-1) - e^(0)
= 1/e - 1

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