# Thread: Help with rate of change and derivatives?

1. ## Help with rate of change and derivatives?

I have these two questions:Are my answers right? I'm not completely sure about them. I don't think the first one can give the instantaneous rate of change because it isn't a limit, is it? Or do you think that might be a typo? (It's just a participation online practice quiz but I want to know if I did them right anyway.) The second one took forever for me to figure out and it came close to the option I chose but I actually got something a tiny bit different. Is it right? Thanks!

2. ## Re: Help with rate of change and derivatives?

Both answers are correct. In the first problem using the value at 3.1 will give an approximation of the slope, but isn't exact. For the second one - the fourth choice is correct, and if you didn't get that try again. Perhaps start by telling us what you got for the first derivative dy/dx?

3. ## Re: Help with rate of change and derivatives?

Originally Posted by ebaines
Both answers are correct. In the first problem using the value at 3.1 will give an approximation of the slope, but isn't exact. For the second one - the fourth choice is correct, and if you didn't get that try again. Perhaps start by telling us what you got for the first derivative dy/dx?
I realized right after posting this what I did wrong for the second one, it was just a stupid addition mistake. Thank you!