Which functions are not one-to-one functions?

Answer:
n(x) and m(x)
Step-by-step explanation:
One-one functions are the ones which have only one input for every output
All linear functions are one-one.
f and g are one-one
n is not a one-one function,
Example:
For, n(x) = 5
x = -1 or -11 (many-one)
m(x) = x⁴-x³+8x-1 is also a many-one. All even degree functions are many-one
Example m(x) = 1
x⁴-x³+8x-1 = 1
x⁴-x³+8x = 0
x(x³-x²+8) = 0 clearly has more than one x value because a cubic has atleast one root, and x=0 is also a root.