Question

If f''(x)=2x^2-3x+1 then...

A. f(x) is concave up on (0.5,∞)
B. f(x) is concave down on (-∞,0.5)
C. f(x) is concave up on (-∞,0.5)
D. f(x) is concave down on (0.5,∞)

Answer 1

It's either A or B... I can't figure out which one... :/

Answer 2

f''(x) > 0 means f'(x) is increasing, it must be concave upwards
f''(x) < 0 means f'(x) is decreasing, it must be concave downwards.

Answer 3

http://www.wolframalpha.com/input/?i=y%3D2x^2-3x%2B1

concave downwards between points 0.5 and 1 ... rest concave upwards

Answer 4

CCC

Answer 5

thanks