Find the curve given the tangent

In summary: So the curve is just a circle with radius 1, center (0,0).In summary, the given problem is to find c(t) when the tangent to the curve at any point is T(t) = (-sin(t), cos(t)) and the curve passes through the point (0,0). Using the given information, it can be determined that c(t) is a circle with radius 1 and center (0,0).
  • #1
madachi
29
0

Homework Statement



Given that the tangent to the curve [itex] c(t) [/itex] at any point on the curve is [itex] T(t) = (-sin(t), cos(t) )[/itex], find [itex] c(t) [/itex] if the curve passes through the point [itex] (0,0) [/itex].

The Attempt at a Solution



I try to let
[itex] c(t) = ( x(t), y(t) ) [/itex]
Then
[itex] c'(t) = ( x'(t), y'(t) ) [/itex]
[itex]| c'(t) | = \sqrt{[x'(t)]^2 + [y'(t)]^2 } [/itex]
And
[itex] T(t) = \frac{c'(t)}{|c'(t)|} [/itex]

However this is complicated and consequently I am not sure how to solve it. I am also not sure how to "use" the point given since (0, 0) correspond the the values x and y respectively rather than t.

Thanks.
 
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  • #2
If you had c'(t) =<2t,1> then c(t) = <t2+A,t+B> where A,B=constant.


But you have

c'(t)/|c'(t)| = <-sint,cost>

so what is c(t) ? (note that |c'(t)| is just a constant)

At (0,0), t=0. So what is c(t) now?
 
  • #3
rock.freak667 said:
If you had c'(t) =<2t,1> then c(t) = <t2+A,t+B> where A,B=constant.


But you have

c'(t)/|c'(t)| = <-sint,cost>

so what is c(t) ? (note that |c'(t)| is just a constant)

At (0,0), t=0. So what is c(t) now?

c(t) = (cos(t) + C, sin(t) + K)
t= 0, point is (0,0)

So x(t) = 1 + C = 0, C = -1
And y(t) = 0 + K, K=0

So c(t) = (cos(t) -1 , sin(t) ) ?
 
  • #4
madachi said:
c(t) = (cos(t) + C, sin(t) + K)
t= 0, point is (0,0)

So x(t) = 1 + C = 0, C = -1
And y(t) = 0 + K, K=0

So c(t) = (cos(t) -1 , sin(t) ) ?

Yes but you forgot out |c'(t)| which is the distance from the center to any tangent. In this case it would just be the same as |T(t)|
 

FAQ: Find the curve given the tangent

What is "Find the curve given the tangent"?

"Find the curve given the tangent" is a mathematical problem that involves finding the equation of a curve or function when only the tangent line at a specific point on the curve is known.

Why is it important to be able to find the curve given the tangent?

Being able to find the curve given the tangent can be useful in various applications, such as in physics, engineering, and economics. It allows us to predict the behavior of a system or function at a specific point, even if we do not have the full equation.

What information do I need to find the curve given the tangent?

To find the curve given the tangent, you need the coordinates of the point where the tangent line intersects the curve and the slope of the tangent line at that point. These pieces of information can be obtained from a graph or given in a problem statement.

What is the process for finding the curve given the tangent?

The process for finding the curve given the tangent involves using the point-slope form of a line and the derivative of the curve. First, you plug in the coordinates of the point and the slope into the point-slope form to get the equation of the tangent line. Then, you use the derivative to find the slope of the curve at that point. Finally, you set the two slopes equal to each other and solve for the equation of the curve.

Are there any limitations to finding the curve given the tangent?

Yes, there are some limitations to finding the curve given the tangent. This method only works if the curve is differentiable at the point where the tangent line intersects it. It also assumes that the tangent line is a good approximation of the curve at that point. Additionally, it may be difficult to find the exact equation of the curve, and an approximation may be necessary.

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