locus question (1 Viewer)

[astroman]

find the equations of the tangent and normal to the parabola x²=16y at the point where x=4.

answers are:
x-2y-2=0
2x+y-9=0

 

[BLIT2014]

http://www.mathsrevision.net/advanced-level-maths-revision/pure-maths/calculus/tangents-and-normals

You need to differentiate first

So x^2 would be 2x

x=2x4=8
16/8x=2y

and remember y=mx+b