Which of the following is an odd function? f(x) = 3x2 + x f(x) = 4x3 + 7 f(x) = 5x2 + 9 f(x) = 6x3 + 2x

f(x) = 4x^3 + 7

Explanation:

Odd function: f(-x) = -f(x)

f(x) = 4x^3 + 7
f(-x) = 4(-x)^3 + 7
f(-x) = -4x^3 + 7
f(-x) = -1(4x^3 + 7)

But 4x^3 + 7 = f(x)

Thus, f(-x) = -f(x)

So this function is odd