# For the scalar function T=e^(-r/5)cos phi, determine its directional derivative along the radial direction hat(r) and then evaluate it at P(2, pi/4.3)

For the scalar function $T={e}^{-r/5}\mathrm{cos}\varphi$ , determine its directional derivative along the radial direction $\stackrel{^}{r}$ and then evaluate it at $P\left(2,\pi /4.3\right)$.
You can still ask an expert for help

## Want to know more about Derivatives?

• Questions are typically answered in as fast as 30 minutes

Solve your problem for the price of one coffee

• Math expert for every subject
• Pay only if we can solve it

Rihanna Robles
$▽\left({e}^{-\frac{r}{5}}\mathrm{cos}\left(\varphi \right)\right)=\left(\frac{\frac{-{e}^{\frac{r}{5}}\mathrm{cos}\left(\varphi \right)}{-{e}^{\frac{r}{5}}\mathrm{sin}\left(\varphi \right)}}{\frac{r}{0}}\right)$. Evaluated at $P\left(2,\pi /4,3\right)=\left(-1/5,-1/2.0\right)1/\left(\sqrt{2}{e}^{\frac{2}{5}}\right)$