Which is a cubic function? a. f(x) = 3x + 1 b. f(x) = 3x2 + x + 2 c. f(x) = 5x3 + 2x + 1 d. f(x) = x3 + x4 + 5

Option C is a cubic function

Step-by-step explanation:

Given the options we have to choose the cubic function

Cubic function is the function with degree 3 i.e the highest power of variable is 3.

Option a:

The above polynomial has highest power 1 i.e of degree 1

∴ not a cubic function

Option b:

The above polynomial has highest power 2 i.e of degree 2

∴ not a cubic function

Option c:

The above polynomial has highest power 3 i.e of degree 3

∴ above is a cubic function

Option d:

The above polynomial has highest power 4 i.e of degree 4

∴ not a cubic function