Find the linearization of the function f(x,y) = xsqrt(y) at the point (9,4).

Answer 1

f(x,y) = x√y, (9,4); f_x = √y; f_y = x/(2√y); f(9,4) = 18; f_x(9,4) = 2; f_y(9,4) = 9/4

L(x,y) = 18 + 2(x - 9) + 9/4(y - 4); L(x,y) = 2x + 9/4y - 9