# on the graph of y=2e^x are drawn the tangent and normal to the curve at the pt.G(p,q)

• Mar 23rd 2008, 09:08 PM
Cement
on the graph of y=2e^x are drawn the tangent and normal to the curve at the pt.G(p,q)
on the graph of y=2e^x are drawn the tangent and normal to the curve at the pt.G(p,q)

a) Find the gradient of the tangent at G in terms of q.
b) Find the equation of the tangetn and normal to the curve at point G

I think i have the right answers for these, but when i go to part c is doesn't seem to work/gets messy.
a) q=2e^p
b) tangent= 2xe^p-2pe^p + q
and normal= -x/2e^p + p/2e^p+ q

Uploaded is a picture of the graph with the tangent and normal.

I also have to find out the co-ordinates of the points A, B, C, D,E and F in terms of p and q. I have worked out B and E but i have no idea how to even begin wiht the others.

I dont necessarily want the answer, just a way in which to do it.
Cheers.
• Mar 23rd 2008, 09:36 PM
o_O
You didn't upload the image. Mind doing that for us? Your part a and b looks fine to me.
• Mar 23rd 2008, 09:46 PM
Cement
Sorry, must've forgotten

here it is.
• Mar 23rd 2008, 09:55 PM
o_O
I'm not sure what E and B are referring to but it looks like they're the same point as G?

F is the y-intercept of your normal line. From your pre-calculus days, what do you do to find it? Similarly, C is your x-intercept.

D is the y-intercept of your tangent line and A is its x-intercept.
• Mar 23rd 2008, 10:07 PM
Cement
ah k thanks lol thats kinda obvious now u pointed it out :P(Headbang)

thanks heaps(Giggle)