posted by Steven .
The linearization at a=0 to sqrt(1+6x) is A+Bx where A is: ____ and where B is : ______
Thus the slope of the curve is 3 at x=0.
f(0)=1 means that the tangent to the curve passes through (0,1)=(x0,y0).
So the linearization is
Identify A and B for your answer.