Identify the integrating factor μ(x)\mu(x)μ(x) for the linear differential equation dydx+4y=ex\frac{dy}{dx} + 4y = e^xdxdy+4y=ex.
μ(x)=4\mu(x) = 4μ(x)=4
μ(x)=x4\mu(x) = x^4μ(x)=x4
μ(x)=e4x\mu(x) = e^{4x}μ(x)=e4x
μ(x)=e−4x\mu(x) = e^{-4x}μ(x)=e−4x