Answer
a) $3x+4y-6$ b) $0$
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 $L(1,1)=1+3(x-1)+(4)(y-1)=3x+4y-6$
b) Since, we have $L(x,y)=z_0+f_x(x-a)+f_y(y-b)$ ...(1)
Now,
$f_x=0$; and $f_y=0$
Now eq. (1) becomes $L(0,0)=0+0(x-0)+0(y-0)=0$
Hence, a) $3x+4y-6$ b) $0$
