Calc Question: Finding Secant Slope?

[sjaguar13]

I wrote down the notes from class, but when I tried to do the homework, I am not even close to the right answers. The formula I wrote down is:
$$\frac{-1}{(x)(x+h)}$$
Apparently that's wrong. Anyone know what it's supposed to be?

 

[Sirus]

Do you mean the derivative of $$f(x)=\sec x$$? In that case it's $$\sec{x}\tan{x}$$.

 

[sjaguar13]

The point $$\mbox(p(1,\frac{1}{2}))$$ lies on the curve $$y=\frac{x}{1+x}$$.
If $$Q$$ is the point $$(x,\frac{x}{(1+x)})$$, use your calculator to find the slope of the secant line $$PQ$$ for the following value of $$x$$: 0.5

I get -2, but it's really .33333.

 

[dextercioby]

The slope is simply
$$a=\frac{y_{1}-y_{2}}{x_{1}-x_{2}}$$

and i get 1/3...

Daniel.