Registered User
Join Date: May 2007
Location: Niles
Posts: 2,761
Location: Niles
Sportbike: 05 CBR600RR
Years Riding: 1 year
How you found us: CBR Forum
(a)
fx = 6x^2+0-12x-0+2-0 = 6x^2-12x+2
Use the chain rule. d/dx(y^2) = 0, d/dx(-4y) = 0, d/dx(-2) = 0
fy = 0+2y-4+0-0 = 2y-4
Use the chain rule. d/dy(2x^3) = 0, d/dy(2x) = 0, d/dy(-2)
(b)
fxx = d/dx(fx) = d/dx(6x^2+2) = 12x-12
fxy = d/dy(fx) = d/dy(6x^2 + 2) = 0
d/dy(6x^2) = 0, d/dy(2) = 0
fyy = d/dy(fy) = d/dy(2y-4) = 2
I don't remember how to find the critical points of a multi variable function, I would have to look that up. But basically, you take the derivative and set that equal to zero and solve for X (in the single variable case). I'm sure its something similar. For extrema and saddle points, I don't remember that either. Would have to look it up.
Quote:
In motorcycle terms, that's like taking your Ducati to a dealer for service, and they hand you back a 1979 backfiring Honda 400 Hawk.. because after all, a bike is a bike.
Last edited by AgentofDarkness; 05-13-2009 at 11:02 AM.