- #1
Mdhiggenz
- 327
- 1
Homework Statement
Hey guys I'm having a hard time understanding how the book obtained the solution.
Here is the question
A function f is given along with a local linear approximation of L to f at a point P. Use the information given to determine point P.
f(x,y)= x2+y2; L(x,y)=2y-2x-2
Formula for local linear approximation is
f(x,y)+fx(x,y)+fy(x,y)=L(x,y)
So plugging in my known values
x02+y02+2x0(x-x0)+2y0(y-y0)=x2+y2
I was able to get up to here, and then when I looked at the solution in the book, it simply said x0=-1 y0 =1 and it isn't obvious to me why.
Any help is appreciated