Step 1: Given f(x)=x2+2x+1x2−8x+12.
Step 2: Domain of function
f(x)=(x+1)2x2−6x−2x+12.
f(x)=(x+1)2x(x−6)−2(x−6)
f(x)=(x+1)2(x−2)(x−6)
It can be seen that the function f is defined for all real numbers except at x=6 and x=2.
Hence, the domain of the function is R - {2, 6}.