Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

If 
r=| vec(r)|, where 
vec(r)=x hat(ı)+y hat(ȷ)+z hat(k), then prove that 
vec(grad).
*** END OF PAPER ***

If r=r r=|\vec{r}| , where r=xı^+yȷ^+zk^ \vec{r}=x \hat{\imath}+y \hat{\jmath}+z \hat{k} , then prove that \vec{\(\newline\)abla} .\newline*** END OF PAPER ***

Full solution

Q. If r=r r=|\vec{r}| , where r=xı^+yȷ^+zk^ \vec{r}=x \hat{\imath}+y \hat{\jmath}+z \hat{k} , then prove that \vec{\(\newline\)abla} .\newline*** END OF PAPER ***
  1. Identify vector and magnitude: Identify the vector r\vec{r} and its magnitude rr.\newliner=xi^+yj^+zk^\vec{r} = x \hat{i} + y \hat{j} + z \hat{k}\newliner=x2+y2+z2r = \sqrt{x^2 + y^2 + z^2}
  2. Calculate gradient of rr: Calculate the gradient of rr.
    \(\newlineabla(r) = \newlineabla(\sqrt{x^2 + y^2 + z^2})\)
    Using the chain rule, \(\newlineabla(r) = \frac{1}{2}(2x, 2y, 2z) / \sqrt{x^2 + y^2 + z^2}\)
    = (xr,yr,zr)\left(\frac{x}{r}, \frac{y}{r}, \frac{z}{r}\right)
  3. Recognize unit vector: Recognize that (xr,yr,zr)(\frac{x}{r}, \frac{y}{r}, \frac{z}{r}) is the unit vector of r\vec{r}. Since r=x2+y2+z2r = \sqrt{x^2 + y^2 + z^2}, dividing each component by rr normalizes the vector. Thus, (xr,yr,zr)=rr(\frac{x}{r}, \frac{y}{r}, \frac{z}{r}) = \frac{\vec{r}}{r}

More problems from Simplify radical expressions with variables II