Parabola, tangebt line and Normal Line intersect

mrm0607
Messages
7
Reaction score
0

Homework Statement



Where does the normal line to the parabola y= x - x^2 at the point (1,0) intersect the parabola a second time? Illustrate with a sketch

Homework Equations



y= x - x^2

The Attempt at a Solution



y' = 1-2x

slope of tangent = -1 (after substituting value of x in above eq)

-ve reciprocal of (-1) = 1

equation of normal line is

y - 0 = 1 (x -1)

y = x -1

After this I am not sure how to find the second point of intersection.

I understand there has to be one since parabola is symmetric about its axis.

Thank you.
 
Physics news on Phys.org
You've done everything correct so far. You now have a separate equation and you want to find where it intersects the parabola. By setting the equations equal, you will get your point of intersection.
 
Thank you
 
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...
Back
Top