Write a python program to determine the minimum of below equation using gradient de$-$

scent method.

$f(x,y)=-0\mathrm{.}5+\frac{x+6}{7}+\frac{y+3\mathrm{.}5}{3}+0\mathrm{.}4tan(x^2+y^2)$

Calculate the minimum of the above function and compare with the answer you obtained

in part $1.$

Plot the above function in excel and prove your answer in part I and II $($please include your

plot$).$