Question

(1) Draw a graph of y = x² and find the value of.

(2) Draw the graph of y = 2x² and find the value of.

(3) Draw the graph of and find the value of.

Answer 1

(1)

We need to find the value ofby graphical method.

We form a table for corresponding values of y for different values of x.

Plot the points (0, 0), (1, 1), (–1, 1), (2, 4), (–2, 4) and (, 7) and join them smoothly.

Now, draw the straight line y = 7 parallel to the x-axis. From the intersecting points of the curve and the line y = 7, draw perpendiculars to the x-axis.

Hence,

(2)

We need to find the value ofby graphical method.

We form a table for corresponding values of y for different values of x.

Plot the points (0, 0), (1, 2), (–1, 2), (2, 8), (–2, 8) and (, 6) and join them smoothly.

Now, draw the straight line y = 6 parallel to the x-axis. From the intersecting points of the curve and the line y = 6, draw perpendiculars to the x-axis.

Hence,

(3)

We need to find the value ofby graphical method.

We form a table for corresponding values of y for different values of x.

Plot the points (0, 0), (2, 2), (–2, 2), (4, 8), (–4, 8) and (, 5) and join them smoothly.

Now, draw the straight line y = 5 parallel to the x-axis. From the intersecting points of the curve and the line y = 5, draw perpendiculars to the x-axis.

Hence,