Answer
a) $3x-4y+5$ b) $3x-4y+5$
Work Step by Step
Since, we have $L(x,y)=z_0+f_x(x-a)+f_y(y-b)$ ...(1)
a ) Now,
$f_x=3$; and $f_y=-4$
Now eq. (1) becomes $L(0,0)=5+3(x-0)+(-4)(y-0)=5+3x-4y$
b) Since, we have $L(x,y)=z_0+f_x(x-a)+f_y(y-b)$ ...(1)
Now,
$f_x=3$; and $f_y=-4$
Now eq. (1) becomes $L(1,2)=0+3(x-1)+(-4)(y-2)=3x-4y+5$
