integral from 0 to 5 of (x-5)(x-3)

解答

\int_{0}^{5} (x - 5) (x - 3) d x

\frac{50}{3}

十进制

16.66666 \dots

求解步骤

\int_{0}^{5} (x - 5) (x - 3) d x

乘开

(x - 5) (x - 3) : x^{2} - 8 x + 15

= \int_{0}^{5} x^{2} - 8 x + 15 d x

使用积分加法定则:

\int f (x) \pm g (x) d x = \int f (x) d x \pm \int g (x) d x

= \int_{0}^{5} x^{2} d x - \int_{0}^{5} 8 x d x + \int_{0}^{5} 15 d x

\int_{0}^{5} x^{2} d x = \frac{125}{3}

\int_{0}^{5} 8 x d x = 100

\int_{0}^{5} 15 d x = 75

= \frac{125}{3} - 100 + 75

化简

\frac{125}{3} - 100 + 75 : \frac{50}{3}

= \frac{50}{3}