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.