What is the slope of any line perpendicular to the line passing through #(-9,8)# and #(-1,1)#?

2 Answers
May 20, 2018

#m'=8/7#

Explanation:

First find the slope of this line:

#m=(y_2 - y_1)/(x_2-x_1)#

#m=(1 - 8)/(-1-(-9))#

#m=-7/8#

formula for a perpendicular slope is #m'=-1/m#

#m'=-1/(-7/8) = 8/7#

May 20, 2018

#8/7#

Explanation:

find the slope of the two given points
from the two points slope formula:

#m = (y_2-y_1)/(x_2-x_1)#

#(-9,8) " and " (-1,1)#

#x_1=-9#

#x_2=-1#

#y_1=8#

#y_2=1#

#m = (1-8)/(-1-(-9)) = -7/8#

perpendicular slope means the reciprocal in the opposite sign

so #8/7#