展开 (x^2+y^2)dx+2xydy

解答

展开

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

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

求解步骤

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

乘开

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

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

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

s im pl i f y (cos (a) - 1) (cos (a) + 1)

s im pl i f y (x - 4) (x - 6 + 7) (x - 6 - 7)

e x p an d \frac{π ( - 3 + 2 )}{12}

e x p an d (1 + tan (x))^{3} sec^{2} (x)