calculus ..>steve
posted by yaya on .
Given a function
f(x)2/3x^3+5/2x^23x.
a) Find
i. The inflection point.
ii. The yintercept and xintercept.
b) Sketch the graph of f(x).
i have already try it..but i don't understand.. which graph that is true.. the first or second ? and how to calculate the x,y intercept,and inflection point? i hope you can help me to solve this ..

y = 2/3 x^3 + 5/2 x^2  3x
y' = 2x^2 + 5x  3
y'' = 4x + 5
inflection where y''=0  at x=5/4
intercepts at (0,0)
and at x = 3/8 (5±√57)
Looks like you need to review the meanings of 1st and second derivatives. 
remember that the first derivative gives you the max's and min's and the second derivative tells you concavity and inflection points