The Student Room Group
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>
Competition - post a photo you've taken of nature >>

Natural exp question

The question is as follows: Given that the curve y=e3xy = e^{3x} and y=kxy = k \sqrt{x} touch each other, show that k=6ek = \sqrt{6e}.

Do I have to use any iterative method to prove this?

Thanks
(edited 12 years ago)
Original post by superkinetic


Do I have to use any iterative method to prove this?

Thanks


No.
Reply 2
Avatar for superkinetic
superkinetic
OP
Original post by ghostwalker
No.


So how do I solve this? I tried squaring both sides but stuck. Thanks
Original post by superkinetic
So how do I solve this? I tried squaring both sides but stuck. Thanks


If two curves touch then you know two things regarding their point of contact.

a) They have the same y value at that point.

b) They have the same gradient at that point.

Can you take it from there?
Reply 4
Avatar for superkinetic
superkinetic
OP
Original post by ghostwalker
If two curves touch then you know two things regarding their point of contact.

a) They have the same y value at that point.

b) They have the same gradient at that point.

Can you take it from there?


Same gradient! I never thought of that till you mention it. Thanks!

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you