展开 1/(s(s-1)^2)

解答

展开

\frac{1}{s ( s - 1 ) ^{2}}

\frac{1}{s ^{3} - 2 s ^{2} + s}

求解步骤

\frac{1}{s ( s - 1 ) ^{2}}

(s - 1)^{2} = s^{2} - 2 s + 1

= \frac{1}{s ( s ^{2} - 2 s + 1 )}

乘开

s (s^{2} - 2 s + 1) : s^{3} - 2 s^{2} + s

= \frac{1}{s ^{3} - 2 s ^{2} + s}

s im pl i f y (1 - sec (x)) (sec^{2} (x))

s im pl i f y 2 (x + i y)^{2}

e x p an d A (- 3, - 4) B (2, 11)

e x p an d (1 - a cos (x))^{2}

e x p an d π (482 - \frac{272 2}{15})