How did you get on in your exams??
Any issues you want to address??
I recently sat the AS edexcel maths but have done other subjects in CCEA
Find the coordinates of any turning points on the curve:
determine the nature of these turning points
i think i diff using quotient rule twice or something.
Denominator can't be zero, so 6xe^x - 3x^2e^x = 0
e^x(6x - 3x^2) = 0
Again, e^x can't be zero. Solving the quadratic, gives x = 2 and x = 0. Can easily find out the y co-ords, so I've not done it.
d^2y/dx^2 = [e^x^2(6e^x - 3x^2e^x) - 2xe^x^2(6xe^x - 3x^2e^x)]/(e^x^2)^2
I hope that's right.. gives me the right results.
Sub in x = 2 and d^2y/dx^2 < 0, so therefore a max. x = 0 and d^2y/dx^2 > 0, so it's a minimum.
Hope that helps.