展开 2((sqrt(2))/2 x-(sqrt(2))/2 y)^2

解答

展开

2 (\frac{2}{2} x - \frac{2}{2} y)^{2}

- 2 x y + x^{2} + y^{2}

求解步骤

2 (\frac{2}{2} x - \frac{2}{2} y)^{2}

使用完全平方公式:

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

(\frac{2}{2} x - \frac{2}{2} y)^{2} = (\frac{2}{2} x)^{2} - 2 \cdot \frac{2}{2} x \frac{2}{2} y + (\frac{2}{2} y)^{2}

= 2 (\frac{2}{2} x)^{2} - 2 \cdot \frac{2}{2} x \frac{2}{2} y + (\frac{2}{2} y)^{2}

化简

(\frac{2}{2} x)^{2} - 2 \cdot \frac{2}{2} x \frac{2}{2} y + (\frac{2}{2} y)^{2} : \frac{- 2 x y + x ^{2} + y ^{2}}{2}

= 2 \cdot \frac{- 2 x y + x ^{2} + y ^{2}}{2}

交叉约去公约数:

2

= - 2 x y + x^{2} + y^{2}

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

e x p an d V (2, - 1) y F (4, - 1)

e x p an d \frac{2 y - 5}{( y - 2 ) ( y + 1 )}

e x p an d \frac{4 ( - π ^{2} ( - 1 ) ^{n} n ^{2} + 2 ( - 1 ) ^{n} - 2 )}{π n ^{3}}

e x p an d (t^{2} - 1) d t