化简 (x+3i)^2

解答

化简

(x + 3 i)^{2}

(x^{2} - 9) + 6 x i

求解步骤

(x + 3 i)^{2}

使用完全平方公式:

(a + b)^{2} = a^{2} + 2 ab + b^{2}

(x + 3 i)^{2} = x^{2} + 2 x \cdot 3 i + (3 i)^{2}

= x^{2} + 2 x \cdot 3 i + (3 i)^{2}

2 x \cdot 3 i = 6 x i

(3 i)^{2} = - 9

= x^{2} + 6 x i - 9

Rewrite in standard complex form:

(x^{2} - 9) + 6 x i

= (x^{2} - 9) + 6 x i

e x p an d \frac{- p ^{2} + 10 p + 8}{( p ^{2} + 8 ) ^{2}}

e x p an d (y - 1) \circ (x + 1)

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

e x p an d - 11 (7 + 5)

e x p an d x^{2} + x ln (x) (- x + ln (x))