# Thread: Normal line and a parabola

1. ## Normal line and a parabola

At what point does the normal to at intersect the parabola a second time?

(____,_____)

so i found the tangent line at (1,5) to be y=11x-6 so the normal line would be y=(-1/11)x-6.

i just dont know what to do from here. i guess i dont really get what the question wants

thank you

2. Originally Posted by mybrohshi5
At what point does the normal to at intersect the parabola a second time?

(____,_____)

so i found the tangent line at (1,5) to be y=11x-6 so the normal line would be y=(-1/11)x-6.

i just dont know what to do from here. i guess i dont really get what the question wants

thank you

when a line intersects a parabola, line = parabola

3. thats what i thought too but when i graph the normal line and the parabola the normal line does not even intersect the parabola?

4. Originally Posted by mybrohshi5
thats what i thought too but when i graph the normal line and the parabola the normal line does not even intersect the parabola?
that's because your normal line equation is incorrect.

slope = $\displaystyle -\frac{1}{11}$

point is $\displaystyle (1,5)$

$\displaystyle y - 5 = -\frac{1}{11}(x - 1)$

now change to point-slope form