Question

Use f1(x) = lim(h -> 0) of (f(x+h) - f(x))/h and then find the tangent line of the graph of y = f(x) at x=a.

f(x) = sqrt(2x+1); a=4

Answer 1

So far I keep getting f1(x) = h/(sqrt(2h+2x+1) + sqrt(2x+1)) as h approaches 0, which means f1(x) = 0. That can't be right.