Question

write the equation of the line through each point. use slope intercept form. through (7,1) and perpendicular to y=-x+3.

Answer 1

y = -x + 3
do you know what the slope is in this equation ?

Answer 2

no.

Answer 3

y = mx + b....m is your slope, therefore the slope to that equation is -1.
Understand so far ?

Answer 4

ok got it.

Answer 5

We are looking for a perpendicular line, therefore the slope will change. We want the negative reciprocal of slope -1. That just means " flip " the slope and change the sign. Therefore, the slope we will need will be 1. Understand ?

Answer 6

yes ok.

Answer 7

We will now use point slope formula : y - y1 = m(x - x1)
using slope(m) = 1 and (7,1) x1 = 7 and y1 = 1
so lets sub our info into the formula..
y - 7 = 1(x - 1)
you still with me ?

Answer 8

yes.

Answer 9

y - 7 = 1(x - 1)
y - 7 = x - 1
y = x - 1 + 7
y = x + 6

any questions ?

Answer 10

thx and i have no questions.

Answer 11

if you were looking for a parallel line, the slope would have stayed the same. But perpendicular is negative reciprocal of the slope. Remember this.

Answer 12

ok thx again.

Answer 13

glad to help :)