Question

given that f is differentiable function with f(2,5) = 6, fx(2,5)=1 and fy(2,5) =-1, use the linear approximation to estimate f(2.2,4.9)

Answer 1

http://en.wikipedia.org/wiki/Linear_approximation

\[f(2.2,4.9) = 6+(2.2-2)- (4.9-5)\]

Answer 2

wait i still kinda confused !! which formula did u use to figure it out ? can u please explain

Answer 3

the formula for f(x,y)

it uses a and b which represent 2 and 5 in your problem
the partial derivatives were 1 and -1 respectively

Answer 4

okay thanks a lot !! got it