Question

11.10. The points (2, 4) and (-2,-4) are plotted on thecoordinate plane using the equation y=a.x.How can you use the coordinates to find thevalue of a?..

Answer 1

Given:

The equation of the line is y = ax.

The coordinates are given as,

$\begin{gathered} (2,4) \\ (-2,-4) \end{gathered}$

The objective is to find the value of a using the coordinates.

Explanation:

The general formula of a straight line is,

$y=mx+b\text{ . . . . . (1)}$

Here, m represents the slope of the straight line and b represents the y-intercept.

Similarly, the general formula to find the value of slope m is,

$m=\frac{y_2-y_1}{x_2-x_1}\text{ . . . . . (2)}$

To find a:

By comparing the given equation with the equation (1),

$m=a$

Consider the given coordinates as,

$\begin{gathered} (x_1,y_1)=(2,4) \\ (x_2,y_2)=(-2,-4) \end{gathered}$

To find the value of a substitute the given coordinates in equation (2).

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