展开 (r*(4r^2sin^2(θ)-r^4))/2

解答

展开

\frac{r \cdot ( 4 r ^{2} sin ^{2} ( θ ) - r ^{4} )}{2}

2 r^{3} sin^{2} (θ) - \frac{r ^{5}}{2}

求解步骤

\frac{r ( 4 r ^{2} sin ^{2} ( θ ) - r ^{4} )}{2}

乘开

r (4 r^{2} sin^{2} (θ) - r^{4}) : 4 r^{3} sin^{2} (θ) - r^{5}

= \frac{4 r ^{3} sin ^{2} ( θ ) - r ^{5}}{2}

使用分式法则:

\frac{a \pm b}{c} = \frac{a}{c} \pm \frac{b}{c}

\frac{4 r ^{3} sin ^{2} ( θ ) - r ^{5}}{2} = \frac{4 r ^{3} sin ^{2} ( θ )}{2} - \frac{r ^{5}}{2}

= \frac{4 r ^{3} sin ^{2} ( θ )}{2} - \frac{r ^{5}}{2}

数字相除:

\frac{4}{2} = 2

= 2 r^{3} sin^{2} (θ) - \frac{r ^{5}}{2}

e x p an d 5 (7 - x = 31 - x)

e x p an d (1 - \frac{4}{x}) e^{x}

e x p an d \frac{11 ( 3 11 + 3 3 - 3 - 33 )}{12}

e x p an d \frac{( ( s cos ( θ ) ) - w ( sin ( θ ) ) )}{( s + a ) ( s ^{2} + w ^{2} )}

e x p an d \frac{3 x ^{2} - 27 x ^{4}}{x ^{3}}