Question

Given the function f(x)=x3
, on what interval of x-values is the graph of f(x)
concave up?(1 point)
Responses

(0,∞)
left parentheis 0 comma infinity right parenthesis

(−∞,0)
left parentheis negative infinity comma 0 right parenthesis

(0,0)
left parentheis 0 comma 0 right parenthesis

(−∞,∞)

Answer 1

f(x)=x^3 → f''(x)=6x.
f''(x)>0 when x>0, so the graph is concave up on (0, ∞).