展开 (dz+2dy)(z+1)

解答

展开

(d z + 2 d y) (z + 1)

z d z + d z + 2 z d y + 2 d y

求解步骤

(d z + 2 d y) (z + 1)

使用 FOIL 方法:

(a + b) (c + d) = a c + a d + b c + b d

a = d z, b = 2 d y, c = z, d = 1

= d zz + d z \cdot 1 + 2 d yz + 2 d y \cdot 1

= z d z + 1 \cdot d z + 2 z d y + 2 \cdot 1 \cdot d y

化简

z d z + 1 \cdot d z + 2 z d y + 2 \cdot 1 \cdot d y : z d z + d z + 2 z d y + 2 d y

= z d z + d z + 2 z d y + 2 d y

e x p an d \frac{3 ( 5 - 1 )}{4}

e x p an d (5 x^{2} + 3 x) l e f t (2 x^{3} - x^{2})

e x p an d \frac{sin ( x ^{2} )}{( x + 5 ) ( x + 4 )}

\frac{\partial}{\partial y} ((p (y, x)) (x - y))

s im pl i f y (t + π) e^{- in wt}