Question

21. Find if f (,y)= x2 + 3xy + y-1: = x A 28-3 (В) 2x (C 2x+3 (D 3y​

Answer 1

Answer:

Correct option is

B

−1

x3−y3+3xy2−3x2y+1=0

dxdy=δyδfδxδf

Substitute  f=x3−y3+3xy2−3x2+1

(δxδf)=3x2+3y2−6x

(δxδf)(0,1)=3

Again f=x3−y3+3xy2−3x2−3x2y+1

(δyδf)=−3y2+6xy−6x

(δy

this is answer