Question

The line through the points $(h,3)$ and $(4,1)$ intersects the line $7x-9y-19=0$, at right angle. Find the value of h.

Answer 1

Slope of $7x-9y-19=0$ is $7/9$

Slope of line perpendicular to it $=-9/7$

So, slope of line passing through $(4,3)$ and $(4,1)$ must be $-9/7$

So, $\frac{1-3}{4-h}=\frac{-9}{7}$

On solving we get

$h=\frac{22}{9}$