展开 (w(z)=2,-4i)(z=1+i)

解答

展开

(w (z) = 2, - 4 i) (z = 1 + i)

w (z) = 5

求解步骤

(w (z) = 2, - 4 i) (z = 1 + i)

= (2 =, w (z) - 4 i) (1 = z + i)

使用 FOIL 方法:

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

a = w (z) = 2,, b = - 4 i, c = z = 1, d = i

w (z) = 2, z = 1 + w (z) = 2, i + (- 4 i) z = 1 + (- 4 i) i

使用加减运算法则

+ (- a) = - a

w (z) = 2, z = 1 + w (z) = 2, i - 4 i z = 1 - 4 ii

乘开

1 - 4 ii : 5

w (z) = 5

e x p an d (5 + 3) 8 - 25

e x p an d \frac{x ( x + 8 )}{2}

so l v e f or y, 3 y + 5 x = 6

e x p an d (x - u) d x - (x + 3 u) (u d x + x d u)

e x p an d c u r l (4 y x^{2}, x + 3 x y^{2})