- #1

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Consider the curve defined by y=x/(x+1). (1,2) is a point NOT on the curve.

Find the equations of the two tangent lines to the curve passing through the point

(1,2).

- Thread starter davedave
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- #1

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Consider the curve defined by y=x/(x+1). (1,2) is a point NOT on the curve.

Find the equations of the two tangent lines to the curve passing through the point

(1,2).

- #2

djeitnstine

Gold Member

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This is perhaps tedious to say the least but I don't know how else to tackle the problem without any more information.

btw winplot should help with this.

- #3

tiny-tim

Science Advisor

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Write y = ax + b for a typical line.

What is the restriction on a and b for it to pass through (1,2)?

Now find the equation for the points of intersection of that line with y=x/(x+1).

That should be a quadratic equation.

What is the condition for that equation to have two equal roots?

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