Determine the open intervals on which the graph of fx7x2x8 i

Determine the open intervals on which the graph of f(x)=7x^2-x+8 is concave downward or concave upward

A.concave upward on (-inf,1): Concave downward(1,inf)

B.concave on (-inf,inf)

C.concave downward (-inf,0) : concave upward (0,inf)

D. concave upward on (-inf,inf)

E.. Concave upward on (-inf,0): concave on (0,inf)

Experts only!!

Solution

f\'(x) = 14x - 1 f\'\'(x) = 14....always positive hence always concave upward.....option d