Slope of a secant line example 3 : Khan Academy on a Stick

Khan Academy on a Stick

Using secant line slopes to approximate tangent slope

Slope of a line secant to a curve
Slope of a secant line example 1
Slope of a secant line example 2
Slope of a secant line example 3
Approximating instantaneous rate of change word problem
Approximating equation of tangent line word problem

If the above player doesn't work, try this direct link.