integral from 0 to a of xsqrt(a^2-x^2)

解答

\int_{0}^{a} x a^{2} - x^{2} d x

\frac{( a ^{2} ) ^{\frac{3}{2}}}{3}

求解步骤

\int_{0}^{a} x a^{2} - x^{2} d x

使用换元积分法

= \int_{a^{2}}^{0} - \frac{u}{2} d u

提出常数:

\int a \cdot f (x) d x = a \cdot \int f (x) d x

= - \frac{1}{2} \cdot \int_{a^{2}}^{0} u d u

使用幂法则

= - \frac{1}{2} [\frac{2}{3} u^{\frac{3}{2}}]_{a^{2}}^{0}

带入上下限计算后得:

- \frac{2}{3} (a^{2})^{\frac{3}{2}}

= - \frac{1}{2} (- \frac{2}{3} (a^{2})^{\frac{3}{2}})

化简

= \frac{( a ^{2} ) ^{\frac{3}{2}}}{3}

x \to 3 lim (\frac{5}{x - 3})

\int_{0}^{2} \frac{2 x}{x ^{2} - 4} d x

\int 9 + 12 cos (x) + 4 cos^{2} (x) d x

t a y l or x 4

f^{^{'}} (x) = 1.9181 \cdot x^{2} + 177.69 \cdot x - 0.4 \cdot x^{3}