展开 3(x+dx)^2

解答

展开

3 (x + d x)^{2}

3 x^{2} + 6 x d x + 3 d x^{2}

求解步骤

3 (x + d x)^{2}

(x + d x)^{2} = x^{2} + 2 x d x + d x^{2}

= 3 (x^{2} + 2 x d x + d x^{2})

打开括号

= 3 x^{2} + 3 \cdot 2 x d x + 3 d x^{2}

数字相乘:

3 \cdot 2 = 6

= 3 x^{2} + 6 x d x + 3 d x^{2}

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

e x p an d e^{8 t} \cdot t (f (t - 8) H (t - 8))

e x p an d (- 7, - 2) y (- 6, 7)

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

e x p an d \frac{4 x ^{2} - 6 x}{3 ( x - 3 ) ( x ^{2} + 9 )}