Question

A line is perpendicular to the line for equation 9y=x+13 .what’s the slope of the perpendicular

Answer 1

That perpendicular line will have slope , negative reciprocal to the slope of this line:

x +9y - 2 = 0 and its slop is - 1/9 { 9y = - x - 2 → y = (-1/9 )x - 2/9 }

So the slope of the perpendicular line will be ? 9

There fore the equation of the perpendicular line : y = 9x + b

“b” to be found by using other conditions

x intercept for this line ( put y = 0 ): -b/9

x intercept for 2x - 9y + 27 = 0 ( put y = 0) : - 27/2

Just equate the two: -b/9 = -27/2 → b = 243/2

y = 9x + 243/2