Finding the Tangent Line to a Parametric Curve

Hobold
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Homework Statement



This is a very basic problem, though it did confuse me a little:

Find the tangent equations to the curve x=3t^2+1 \ , \ y = 2t^3+2 which intercepts the point (4,3).

Homework Equations



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The Attempt at a Solution



I took \frac{dy}{dx} = t = \frac{y-y_0}{x-x_0} = \frac{y-3}{x-4} \rightarrow y=t(x-4)+3

What to do next? I don't think the equation works for all t.
 
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Hobold said:

Homework Statement



This is a very basic problem, though it did confuse me a little:

Find the tangent equations to the curve x=3t^2+1 \ , \ y = 2t^3+2 which intercepts the point (4,3).
Are you sure the above is right? If x = 4, then t = +/-1, but when t = 1, y = 4 and when t = -1, y = 0.
Hobold said:

Homework Equations



---

The Attempt at a Solution



I took \frac{dy}{dx} = t = \frac{y-y_0}{x-x_0} = \frac{y-3}{x-4} \rightarrow y=t(x-4)+3

What to do next? I don't think the equation works for all t.
 
Yes, I'm sure, those are the functions.

I believe the problem asks for a tangent of the graphic which will intercept the point (4,3) in R^2, which is not necessarily in the graphic of the function.
 
OK, I misunderstood.

So let's say we're talking about the point on the curve whose coordinates are (x0, y0), that correspond to t = t0.

Can you use the parametric equations to write x0 and y0 in terms of t0. Then use the point (4, 3) and calculate the slope of the line segment between (x0, y0) and (4, 3), which you know is equal to t0.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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