Write an equation of the line that passes through (2,−3) and is perpendicular to the line y=−2x−3.

Question

Write an equation of the line that passes through (2,−3) and is perpendicular to the line y=−2x−3.

Answer 1

Hi Zachary,

The easiest way to answer this would be by using the slope-intercept form equation, y=mx+b. In this case, we can use our given in information to plug in values and find the equation.

Firstly, let's assess what know and what we don't:

Given the point (2,-3), we know that x=2 and y=-3. Now the slope for a perpendicular line can be found using a negative reciprocal, since the product of the slopes of both lines should equal -1. Therefore the slope must be 2.

All that's left is b, the y-intercept. To solve for this, we simply plug in what we have.

y=mx+b

-3=2(2)+b

-3=4+b

-3-4=b

-7=b

Now that we have b, we can write the equation:

y=2x-7