### Home > PC3 > Chapter 10 > Lesson 10.1.4 > Problem10-90

10-90.

Use a calculator to graph the function $f(x) = \frac { 12 x } { x ^ { 2 } + 4 }$, determine where the function is:

1. increasing

1. decreasing

1. concave up

1. concave down

Trace the curve from left to right with your finger. When your finger moves 'uphill' the function is increasing.

The curve is concave up where it looks like a cup that is right-side up.