Question

What is a zero of a function?

Answer 1

A zero of a function is an interception between the function itself and the X-axis.
The possibilities are:

• no zero (e.g. `y=x^2+1`) graph{x^2 +1 [-10, 10, -5, 5]}
• one zero (e.g. `y=x`) graph{x [-10, 10, -5, 5]}
• two or more zeros (e.g. `y=x^2-1`) graph{x^2-1 [-10, 10, -5, 5]}
• infinite zeros (e.g. `y=sinx`) graph{sinx [-10, 10, -5, 5]}

To find the eventual zeros of a function it is necessary to solve the equation system between the equation of the function and the equation of the X-axis (`y=0`).