**One of the other things you'll be
hunting for is the point where the graph changes from concave down
to concave up (and visa versa).
**

**It's called "the point of
inflection."**

**This tangent line stuff was
probably way more than you wanted to know. But, believe me,
it's nice to get to see it all ahead of time before you have all
those Calculus numbers, x's
and formulas flying at you at what will seem like the speed of
light!
**

**YOUR TURN:**

**On the following
graph, draw tangent lines at
x = 1, x = 2, x = 3 , x = 4, x = 5 and x = 6.**

**Where is the graph
concave down?**

**Where is the graph
concave up?**