展开 3(x^2+y^2)dx+7xydy

解答

展开

3 (x^{2} + y^{2}) d x + 7 x y d y

3 x^{2} d x + 3 y^{2} d x + 7 x y d y

求解步骤

3 (x^{2} + y^{2}) d x + 7 x y d y

乘开

3 d x (x^{2} + y^{2}) : 3 x^{2} d x + 3 y^{2} d x

= 3 x^{2} d x + 3 y^{2} d x + 7 x y d y

e x p an d \frac{8 e ^{- π x}}{( x ^{2} + 1 ) ( x ^{2} + 9 )}

e x p an d \frac{2 x ^{2} - 14 x + 21}{( x - 3 ) ^{2}}

e x p an d \frac{2 z ( z + 4 )}{z - 1}

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

e x p an d \frac{0.00034 ( 1 + 7.5 s )}{( 1 + 2 s )}