展开 (2+t)sqrt(9-t^2)

解答

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(2 + t) 9 - t^{2}

2 9 - t^{2} + t 9 - t^{2}

求解步骤

(2 + t) 9 - t^{2}

= 9 - t^{2} (2 + t)

使用分配律:

a (b + c) = ab + a c

9 - t^{2} (2 + t) = 9 - t^{2} \cdot 2 + 9 - t^{2} t

= 9 - t^{2} \cdot 2 + 9 - t^{2} t

= 2 9 - t^{2} + t 9 - t^{2}

e x p an d \frac{e ^{t} ( cos ( t ) - 1 )}{t}

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

s im pl i f y (x + \frac{1}{4}) (x - \frac{1}{4})

e x p an d 7 (5 + 1)

s im pl i f y (1 + \frac{x}{1 - x}) (1 - \frac{x}{1 + x})