calculate the jacobian matrix for the given function at the indicated point. write a formula for the total derivative.

H(r, theta)= (rcostheta, rsintheta) a= (square root of 2, 3pi/2)

so i changed it to H(x,y) and got the matrix

1 0

0 1

but the answer in the back of the book is

0 squ.rt 2

-1 0

i feel like it has to do with the point a but i don't know where i'm supposed to plug this point in? or how to write the formula for the total derivative?

sorry this is my first time doing derivatives in this class so i'm a bit confused