Question

Find the equation of the line that passes through (1,2) and is perpendicular to

y
=
2
x
+
3
.
Leave your answer in the form
y
=
m
x
+
c

Answer 1

Remember that the slope of perpendicular lines are negative reciprocals of each other.

Explanation:

y = 1 - 2x the slope is -2 the value of the x term.

So the slope of the new line using point (- 1, 2) is 1/2.

Now use y = mx + b where y = -1, x = 2, and m = 1/2 .

y = mx + b

-1 = 1/2(2) + b solve for "b", the y-intersect

-1 = 1 + b

-2 = b

The line that is perpendicular to y = 1 - 2x is y = 1/2x - 2