# Function question

• Sep 14th 2009, 11:00 PM
WendyM
Function question
I can't solve this so I hope that you could help me (Thinking)

f(x)=(2x-3)(x-2) What are the values of x which make the function increasing?
• Sep 14th 2009, 11:13 PM
pickslides
You need to find the axis of symmetry. This is halfway between the zeros.

As this function is a positive quadratic all values to the right of this value have the function increasing.
• Sep 14th 2009, 11:13 PM
pflo
Quote:

Originally Posted by WendyM
$f(x) = (2x-3) (x-2)$ What are the values of x which make the function increasing?

If you multiply this out you get $f(x) = 2x^{2} - 7x + 6$. Hopefully you recognize that this quadratic function would graph as a parabola opening upward. It would therefore be increasing everywhere that x is larger than the axis of symmetry (the x coordinate of the vertex).