# Thread: Need Immediate help for this question!!!

1. ## Need Immediate help for this question!!!

1. Given the function f(x) = x^3-2x, sketch y = f(|x|)

2. Sketch g(x) = |x^2-1| - |x^2-4|

3. Sketch the region in the plane to show all points (x,y) such that|x|+|y|<=2

I need help understanding absolute values, cause i plugged in table of values to get y but my teacher says I have to consider the cases and regions which I don't understand. Please help asap.

2. Originally Posted by shane99
1. Given the function f(x) = x^3-2x, sketch y = f(|x|)

2. Sketch g(x) = |x^2-1| - |x^2-4|

3. Sketch the region in the plane to show all points (x,y) such that|x|+|y|<=2

Answer one of these questions in detail, do not leave anything. Also remember not to simplify anything, and I'm looking for you guys to clearly explain to me about the cases and region of each equation(my teacher said something about that). Most importantly answer the bloody questions!!!
Shane, we don't do peoples' homework for them here at MHF. Tell us what you have tried and where you are stuck.

3. I already handed it in and it was marked poorly so I need to know how to do this. Here's what I did, I plugged in 5 values of x into the equation and got five f(x) values which I used to graph it, and then my answers was matching the answer in the back of the book. However, my teacher gave me a really poor mark on it all because I didn't consider the cases and regions, which your gonna have to explain to me for these questions because I do not what she's talking about.

4. Originally Posted by shane99
I already handed it in and it was marked poorly so I need to know how to do this. Here's what I did, I plugged in 5 values of x into the equation and got five f(x) values which I used to graph it, and then my answers was matching the answer in the back of the book. However, my teacher gave me a really poor mark on it all because I didn't consider the cases and regions, which your gonna have to explain to me for these questions because I do not what she's talking about.
No, we're not 'gonna' explain anything. You're teacher is. When you go and see him/her.