How do I find the test intervals for graphing a Quadratic Inequality on a line graph? Example: x^2-5x+4

Question

How do I find the test intervals for graphing a Quadratic Inequality on a line graph? Example: x^2-5x+4<0

anonymous · Answer

Well, your first step would be to change this inequality to an equation, simply replace the < with =. Then factor and set each term to zero

anonymous · Answer

I have the factor to (x-4)(x-1) But how do I find the test intervals?

anonymous · Answer

now, find x, by setteing each term to zero and solving

anonymous · Answer

x is 4 and x is 1...graph on line graph, but to find where to graph I need to find the test intervals.

anonymous · Answer

okay, now the intervals will simply be :

$$(-\infty,1),(1,4)(4-\infty)$$

anonymous · Answer

then pick a point in each interval and test

anonymous · Answer

So you pick any point?

anonymous · Answer

yeah, but dont pick  1 or 4