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

D)

Step-by-step explanation:

If it is an odd function, then f(-x) = -f(x)

If we plug in x = -x in f(x), we will get -f(x).

Now we have to check the given functions.

Let's check the function one by one.

f(x) =

Now plug in x = -x in the above function.

f(-x) =

Here f(-x) ≠ -f(x)

It is not an odd function.

Let's check the second function.

f(x) =

This is also not an odd function.

Clearly, iii) f(-x) ≠-f(x)

iv)

Now plug in x = -x, we get

f(-x) =

f(-x) =

f(-x) =

f(-x) = -f(x), this is true.

Therefore, the odd function is D) f(x) = 6x^3 + 2x