91Ó°ÊÓ

The given figure is:

We have to find whether given expression $y_2−y_1$positive or negative.

From the given figure we see that the coordinate $\left(x_2,y_2\right)$is in the fourth quadrant and $\left(x_1,y_1\right)$is in the second quadrant.

So$x_2,y_1$ are positive values and$x_2,y_1$ are negative values.

It means, the value of expression$y_2−y_1$ is negative.

Because$−ve−(+ve)=−ve−ve=−ve$ .

So, the expression$y_2−y_1$ is negative.

The given figure is:

We have to find whether given expression $x_2−x_1$positive or negative.

From the given figure we see that the coordinate$\left(x_2,y_2\right)$ is in the fourth quadrant and$\left(x_1,y_1\right)$ is in the second quadrant.

So$x_2,y_1$ are positive values and$y_2,x_1$ are negative values.

It means, the value of expression$x_2−x_1$ is positive.

Because$+ve−(−ve)=+ve+ve=+ve$ .

So, the expression$x_2−x_1$ is positive.

The given figure is:

We have to find whether given expression $\frac{y_2−y_1}{x_2−x_1}$positive or negative.

From part a, the expression$y_2−y_1$is negative.

From part b, the expression$x_2−x_1$is positive.

So, $\frac{y_2−y_1}{x_2−x_1}=\frac{−ve}{+ve}=−ve$.

It means$\frac{y_2−y_1}{x_2−x_1}$ is negative.