展开 (0.01515+0.216i)*(81,68-3811i)

解答

展开

(0.01515 + 0.216 i) \cdot (81, 68 - 3811 i)

81 \cdot 0.01515, 68 - 3811 \cdot 0.01515 i + 81 \cdot 0.216 i, 68 - 3811 \cdot 0.216 ii

求解步骤

(0.01515 + 0.216 i) (81, 68 - 3811 i)

= (0.01515 + 0.216 i) (81 \cdot 68, - 3811 i)

使用 FOIL 方法:

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

a = 0.01515, b = 0.216 i, c = 81, 68, d = - 3811 i

= 0.01515 \cdot 81, 68 + 0.01515 (- 3811 i) + 0.216 i 81, 68 + 0.216 i (- 3811 i)

使用加减运算法则

+ (- a) = - a

= 81 \cdot 0.01515, 68 - 3811 \cdot 0.01515 i + 81 \cdot 0.216 i, 68 - 3811 \cdot 0.216 ii

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