?

Multivariable Calculus

Free Version

Upgrade subject to access all content

Easy

Which Exact Differential Equations have Solutions

MVCALC-CJEOVX

Which of the following exact differential equations have solutions?

I. $4x\sin y + \left( 2x^2\cos y + 8y \right) \frac{dy}{dx} = \cfrac1x$
II. $xe^{x^2+y^2} + e^{x^2+y^2} \cfrac{dy}{dx} = 1$
III. $\ln x + \sec^2 y \cfrac{dy}{dx} = 0$

A

only III

B

I and II

C

I and III

D

II and III

E

None of the Above