Stuck on chapter polynomial and rational inequalities

[jonah2.0]

Beer induced recall and recommendation follows.

Can someone explain to me how to do polynomial and rational inequalities? Im stuck in the book algebra 1 for dummies workbook. Are there better books then dummies?

Math Full Courses

This playlist features full courses from our free website: https://greenemath.com

youtube.com

Also,
The Humongous Book Of Algebra Problems 2008 W. Michael Kelley

The humongous book of algebra problems : translated for people who don't speak math! : Kelley, W. Michael : Free Download, Borrow, and Streaming : Internet Archive

x, 561 p. : 28 cm

archive.org

Unfortunately, borrowing has been disabled.
There's always free YouTube.

 

[bladeren]

I must exercise on that true in interval thing i geuss

 

[bladeren]

After all those videos and tutorials, i still dont understand qauadratic inequalities. I dont understand how to get a answer with a number line. Can someone help me please

 

[Dr.Peterson]

After all those videos and tutorials, i still dont understand qauadratic inequalities. I dont understand how to get a answer with a number line. Can someone help me please

In order to help without writing a new, perfect book for you, we'll need to see what you don't understand.

Please show your attempt at an example, so we can see where you go wrong, or else show a worked example from somewhere and point out which parts you don't follow. The more you explain of your own specific difficulties, the more we can help.

 

[bladeren]

On previous page you see my attempts on writing paper. I try to explain what i dont understand.. i dont understand how you come to answers and interval notation s from the answers.

 

[Dr.Peterson]

On previous page you see my attempts on writing paper. I try to explain what i dont understand.. i dont understand how you come to answers and interval notation s from the answers.

We've responded to you since that. Clearly we don't fully understand what your difficulty is, and you don't fully understand what we have said. So try again, just you are asking us to try again. We both have to help each other!

Please be as complete as you can about the steps that confuse you, both in what you wrote, and in what I said in response.

 

[bladeren]

Maybe this video is going to help me: https://www.showme.com/sh/?h=yNCES8m

 

[mario99]

Maybe this video is going to help me: https://www.showme.com/sh/?h=yNCES8m

You can do it bladeren. I trust in your abilities. Professor Jambo has once told me that it sometimes takes a lot of time to understand the idea of the new lesson. But once you understand it, you understand it for a lifetime.

 

[Harry_the_cat]

After all those videos and tutorials, i still dont understand qauadratic inequalities. I dont understand how to get a answer with a number line. Can someone help me please

Hey Bladeren. I'm happy to show you a different way to solve quadratic inequalities. How are you at graphing parabolas?

 

[bladeren]

Hey Bladeren. I'm happy to show you a different way to solve quadratic inequalities. How are you at graphing parabolas?

Graphing parabolas is something i can do (with help).

 

[Harry_the_cat]

Great! So here's some questions for you:

1. Do you know how do determine whether \(\displaystyle y=ax^2+bx+c\) opens up like \(\displaystyle \cup\) or down like \(\displaystyle \cap\)?

2. Do you know how to find the x-intercepts of \(\displaystyle y=ax^2+bx+c\) ?

 

[bladeren]

Uhm, i use the dummies workbook. Next to explanation you find a task. Without help of my workbook i cannot complete the task. So i dont know to determine and to find the x-intercept.... Oke, i have much to learn

 

[bladeren]

Mathisfun.com help me and this forum: https://www.freemathhelp.com/forum/...t-included-lost-oversight.136157/#post-579323

 

[Harry_the_cat]

Uhm, i use the dummies workbook. Next to explanation you find a task. Without help of my workbook i cannot complete the task. So i dont know to determine and to find the x-intercept.... Oke, i have much to learn

OK.
If the coefficient of \(\displaystyle x^2\) is positive then the parabola is shaped like \(\displaystyle \cup\).
If it is negative, the parabola is shaped like \(\displaystyle \cap\).

Did you know that?

 

[bladeren]

Now i do This is algebra I stuff. I am between pre-algebra and algebra I.

 

[bladeren]

You can do it bladeren. I trust in your abilities. Professor Jambo has once told me that it sometimes takes a lot of time to understand the idea of the new lesson. But once you understand it, you understand it for a lifetime.

This is me .

 

[Harry_the_cat]

Now i do This is algebra I stuff. I am between pre-algebra and algebra I.

Good. Remember that.
Now, to find the x-intercepts of a parabola (or any graph for that matter):
You know that any point on the x-axis has a y-coordinate of 0. Yes?
So, simply substitute y=0 and solve for x.
So, consider the function \(\displaystyle y=x^2+3x-4\).
Put 0 in for y and solve for x. Can you do that?

 

[bladeren]

Yes i can solve that one

 

[Harry_the_cat]

Yes i can solve that one

View attachment 38413

You've factorised the quadratic expression \(\displaystyle x^2+3x-4\), but you haven't solved the quadratic equation \(\displaystyle x^2+3x-4=0\).

 

[bladeren]

You've factorised the quadratic expression \(\displaystyle x^2+3x-4\), but you haven't solved the quadratic equation \(\displaystyle x^2+3x-4=0\).

Uhm, you mean on a xy-plane? No that is new stuff for me.