Pre-Calc 11 - Lesson 5.1 (Part 1)

Solving Quadratic Inequalities in One Variable

[mathjohnson]

Yes absolutely...but I'll tell you the reason I did it the way I did...Usually I find that students like to have the quadratic on the left side of an inequality, they usually find it easier to interpret...also, by moving the terms to the left side of the equation the x squared term became positive which most students find easier to factor...although many different ways to do it...I hope this helps!

[mathjohnson]

I am suggesting that you set the equation equal to zero. You are therefore finding the roots of your equation (the points at which the graph crosses the x axis, your x-intercepts.) Once you set the equation equal to zero then you factor.

[teacheraredifficult]

This video was super helpful, thanks a ton!!!

[mathjohnson]

Open dot means that I am not including the point on my number line, used for 'less than' or 'greater than' inequalities, rather than a closed dot for the other inequalities.

[GlowingRobot]

Thank you so much for uploading this! I was reading the instructions in the text book and it wasn't making any sense to me, but you totally cleared it up. This definitely helped! Again, thanks so much!

[trishasales]

Could you have done example 3 by moving the -8x to the right side instead of how you did it?

[erinmaxfield]

What do you mean by setting them to zero? at 5:40 ish

[laptopsaysno]

Hi! I'm an adult in SD 40. New Westminster. Thank you so much!!! This follows the Pearson book! I will tell my classmates. you Rock!

[karnvirbhangu]

at 3:14 shouldn't it be 1>x<4?