Homework help?? Midterm is tomorrow!!!

[by76488]

Hi guys, I'm hoping to get some fast help here since I have a midterm tomorrow and I am anything but prepared. I may post more questions later on, hope that's okay. Here is the first one:
1)

So I was able to graph it on my calculator and choose the correct graph, but as you can see by the two red x's I was not able to find the restraints. I know ( ) or [ ] are needed, but what am I doing wrong?

This is another problem:
2)


and 3)


Please help! I am in desperate need of some explanation. Thank you!!

** NOTE: the pictures may be small, just right click and take it to a new tab to see it in a bigger resolution

 

[wjm11]

Hi guys, I'm hoping to get some fast help here since I have a midterm tomorrow and I am anything but prepared. I may post more questions later on, hope that's okay. Here is the first one:
1)
View attachment 5094
So I was able to graph it on my calculator and choose the correct graph, but as you can see by the two red x's I was not able to find the restraints. I know ( ) or [ ] are needed, but what am I doing wrong?

This is another problem:
2)
View attachment 5096

and 3)
View attachment 5097

Please help! I am in desperate need of some explanation. Thank you!!

** NOTE: the pictures may be small, just right click and take it to a new tab to see it in a bigger resolution

In 1), the function is increasing on two separate intervals; you've only listed one of them. The other is (0, +infinity). For the decreasing portion, it should be (-2,0) -- open interval, not closed at zero. The function is neither increasing nor decreasing at x = 0.

In 3), where did you get 100 as the lowest cost??? The answer to the nearest integer is 30. You can sort of "eyeball" that right of the graph... (Alternatively, if you use calculus, you can get a more precise answer.)