Create an equation of a nonlinear function and provide two inputs for your classmates to evaluate

f(x)=(x+2)^2 is an example for non linear equation.

Let us take x=1, x=2.

f(1)=(1+2)^2 =9.

f(2)=(2+2)^2 =16..

Another example is f(x) =ln x.

f(1)= ln 1=0.

f(2) =ln 2.