展开 (-2s+4)/((s^2+1)(s-1)^2)

解答

展开

\frac{- 2 s + 4}{( s ^{2} + 1 ) ( s - 1 ) ^{2}}

\frac{- 2 s + 4}{s ^{4} - 2 s ^{3} + 2 s ^{2} - 2 s + 1}

求解步骤

\frac{- 2 s + 4}{( s ^{2} + 1 ) ( s - 1 ) ^{2}}

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

= \frac{- 2 s + 4}{( s ^{2} + 1 ) ( s ^{2} - 2 s + 1 )}

乘开

(s^{2} + 1) (s^{2} - 2 s + 1) : s^{4} - 2 s^{3} + 2 s^{2} - 2 s + 1

= \frac{- 2 s + 4}{s ^{4} - 2 s ^{3} + 2 s ^{2} - 2 s + 1}

e x p an d - \frac{2 x}{( 1 + x ^{2} ) ^{2}}

e x p an d \frac{s ^{2} + 1}{s ( s - 1 ) ( s + 1 ) ( s - 2 )}

e x p an d (sec (θ) + tan (θ))^{2}

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

s im pl i f y (3 x - 2 i)^{2}