展开 2x(x-1)^2-3cos(pix)

解答

展开

2 x (x - 1)^{2} - 3 cos (π x)

2 x^{3} - 4 x^{2} + 2 x - 3 cos (π x)

求解步骤

2 x (x - 1)^{2} - 3 cos (π x)

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

= 2 x (x^{2} - 2 x + 1) - 3 cos (π x)

乘开

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

= 2 x^{3} - 4 x^{2} + 2 x - 3 cos (π x)

e x p an d \frac{( x ^{2} - 9 ) ( x - 3 ) ( x - 1 )}{( x + 1 ) ( x + 2 )}

e x p an d \frac{1}{( 1 - x ) ^{3}}

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

s im pl i f y (32 a - 2 b)^{2}

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