f(x) = ∫(1→x²) e^(- t)/t dtf'(x) = 2x · e^(- x²)/x² = 2e^(- x²)/xf(1) = 0,∵上限 = 下限∫(0→1) xf(x) dx = ∫(0→1) f(x) d(x²/2)= (1/2)x²f(x)：(0→1) - (1/2)∫(0→1) x...