# Homework Help: Help finding slope of curve

1. Feb 26, 2014

### grace77

Problem statement
F(x)= x^2-3x
P=(1,f(1))

Revelant equation
Lim f(a+h)-f(a)/ (h) As h approaches 0

Attempt at a solution

Now this is where I get stuck.. Because usually you have a h that cancels out and then you have something in the form of (h+a) that can be used to determine the slope.. What do I do next??

2. Feb 26, 2014

### Staff: Mentor

What you got for f(1 + h) is wrong. f(1 + h) = (1 + h)2 - 3(1 + h).

Also, you don't seem to use "=" consistently in your work. You have
$lim_{h \to 0} =$, following by the thing you're taking the limit of, which is incorrect. You also don't connect the expressions you're doing algebra on with an equal sign, nor do you include the "lim" notation. "lim" should go away only when you actually take the limit, not before.

3. Feb 26, 2014

### pasmith

You have made a calculation error:

$$F(1 + h) - F(1) = (1 + h)^2 - 3(1 + h) + 2$$
and not $(1 + h)^2 + 2$ as you have.

4. Feb 26, 2014

### grace77

I see my error now thank you!

5. Feb 26, 2014

### grace77

Thank you for your comments. How do I do the lim notations on physics forum?

6. Feb 26, 2014

### pasmith

Code (Text):

$$\lim_{h \to 0}$$

produces
$$\lim_{h \to 0}$$

7. Feb 26, 2014

### grace77

Is there a guide where I can find all of these notations?

8. Feb 26, 2014

### pasmith

See here.

9. Feb 26, 2014

### grace77

Thank you. You have been a great help!