What will be the curl of this vector??

68 Views Asked by At

If $\vec r=x\hat i+y\hat j+z\hat k$ where $r=|\hat r|$ , and $\vec a$ is a constant vector then find the values of following

1) $\nabla\times(r^n\ \vec r)$

2) $\nabla\times(\vec a\times \vec r)$

My trial:

1) $\ \nabla\times(r^n\ \vec r)=r^n(\nabla\times \vec r)=r^n(0)=0$

2) $\nabla\times(\vec a\times \vec r)=(\nabla\cdot\vec r)\vec a-(\nabla\cdot\vec a)\vec r=3\vec a-0=3\vec a$

I don't know if i have done any mistake or my answers are incorrect. please help me solve these problems. thanks