Question

Draw the graph of the identity function $f:R\to R:f\left(x\right)=x$ for all $xϵR$

Answer 1

Here $f\left(x\right)=x$ for all $xϵR$

We may prepare its table as under.

$$\begin{array}{ccccccc}x& -2& -1& 0& 1& 2& 3\\ f\left(x\right)=x& -2& -1& 0& 1& 2& 3\end{array}$$

On a graph paper, we draw $X^{{}^{\prime }}OX$ and $YO{Y}^{{}^{\prime }}$ as the x-axis and the y-axis respectively.

We take 10 small divisions = 1 unit

Now, on this graph paper, we plot the points

A(-2, -2), B(-1, -1), O(0, 0), C(1, 1), D(2, 2) and E(3, 3)

Join these points successively to obtain the straight line ABOCDE as the required graph line, given below.