# Homework Help: Finding the tangent equations of the curve

1. Nov 11, 2012

### ruiwp13

1. The problem statement, all variables and given/known data

Find the tangent equations to the curve y^2= x-1/x+1 at the points with x=2

2. Relevant equations

y=mx+b

dy/dx

3. The attempt at a solution

I tried to solve in order to y: y=sqrt((x-1)/(x+1))

Then I derived to obtain the slope, but this is the part that I don't know if it is correct. Do I need to derive the equation to get the slope, and after getting the slope I substitute the x in the equation that I got to get the tangent equation? I'm stuck here

Thanks in advance

Last edited: Nov 11, 2012
2. Nov 11, 2012

### Staff: Mentor

from reading your problem you should expect more than one point where x=2.

Next when taking the sqrt you'll have two possible eqns y=+sqrt(...) and y=-sqrt(...)

when you say derive do you mean doing the sqrt or differentiate as in differential calculus?

3. Nov 11, 2012

### ruiwp13

as in differential calculus... but I'm not sure if that's the correct method :p I know I have to take the square out of y. So I'll have too possible equations. But after taking it, I don't know what to do. I'll get y = sqrt((x-1)/(x+1)) or y = -sqrt((x-1)/(x+1))

4. Nov 11, 2012

### Staff: Mentor

whats the definition of derivative? isn't it the slope of a tangent line at that point?

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