# Find the directional derivative of f at the given point in the direction indicated by the angle \theta. f(x,y)=e^x\cos y,(0,0),\theta=\frac{\pi}{4}

Derivatives
Find the directional derivative of f at the given point in the direction indicated by the angle $$\theta. f(x,y)=e^x\cos y,(0,0),\theta=\frac{\pi}{4}$$