Posted by JULIA on .
Given that f(0.5)=2 and f'(0.5)=4, use a tangent line approximation to estimate f(0).
The lesson is not very clear on what a tangent line approximaton is.

Derivatives? 
drwls,
The tangent line approximation is:
f(x) = f(a) + (xa)*f'(a)
It is the formula for a straight line that goes through x = a with the slope of f(x) at x=a.
Let a = 0.5 and x = 0
f(0) = 2 + (0.5)*4 = 4