Question

What is the equation of the line that is perpendicular to the line y = 2x+5 and

passes through the point (-4, 2)?
O A. y = -1/2x+2
B. y = 2x + 6
O C. y = 2x-6
O D. y=-1/2x

Answer 1

y= -1/2x

Explanation:

• perpendicular is the opposite slope so -1/2 is the opposite slope of 2
• y=mx+b to solve for b I was taught to plug in what you have so
• 2= -1/2(-4)+b
• 2=2+b
• subtract 2 on both sides to get b=0

Answer 2

Perpendicular equations have negative reciprocal gradients (so it’s gradient will be -1/2)

And if you draw a quick sketch of the lines A and D (they have the right gradients) then you can see which option is the best fit. I used desmos and option A passes through (-4,2)