Question

A function f(x) = x3 + 2x - 1 has a zero within (0.1). Find the interval that the zero exists.
(A) (0.1, 0.3) (B) (0.4, 0.5) (C) (0.6, 0.7) (D) (0.7. 0.9)

Answer 1

f(0.4) < 0
f(0.5) > 0
so, (B)