The concept of function is very simple.

supposeIi say that:

```
y=5x²
```

where x∈R. this tells that y depends upon x this can be stated that y is a function of x. or

y=f(x)

we can also say that x=3√y here x depends on y or x is a function of y or

x=f(y)

so it can be stated that a function is an operator which has an input and gives an output.The input value is called independent variable while output value is called dependent variable