Find the slope-intercept equation of the line that passes through (-8, 9) and is perpendicular to x - 8y = 2.
Hi keadyjr,
First of all find the slope of your line given by the equation x - 8y = 2. Let's put it in slope-intercept form:
$\displaystyle y=\frac{1}{8}x-\frac{1}{4}$
So the slope is $\displaystyle \frac{1}{8}$
The slope of a line perpendicular to this line would be the negative reciprocal of $\displaystyle \frac{1}{8}$, or $\displaystyle -8$.
Using the point (-8, 9) and a slope of -8, we can now find the y-intercept.
$\displaystyle y=mx+b$
$\displaystyle 9=-8(-8)+b$
$\displaystyle b=-55$
Substituting back into the slope intercept form, we arrive at:
$\displaystyle y=-8x-55$