Question

Write the equation of a line that passes through (-3/2, -5) and perpendicular to a line that contains (-1, -2) and (-2, -8).

Answer 1

find gradient/slope

-8-(-5) / -2-(-1) = -3/-1

= 3

y=3x+c

perpendicular line formula

m1(m2)= -1

(sub in the gradient before)

3(m2)= -1

m2= -1/3 ( perpendicular line gradient)

y=-1/3x+c

(sub in the coordinate)

-5=-1/3(-3/2)+c

-5=1/2+c

-11/2=c (y intercept)

answer: y= -1/3x - 11/2