Find the equation of the line perpendicular to y=2x+6 and passing through (4,5)

Question

Find the equation of the line perpendicular to y=2x+6 and passing through (4,5)

Answer 1

Patrick is right.

What's the slope of the line? It's 2 (y = mx + b), where "m" is the slope.

Perpendicular line is the NEGATIVE reciprocal of the slope (- 1/m) therefore (-1/2)

So, we have y = mx + b. m is found, now we have to find b. Plug in x and y (4, 5) and get b.

5 = (-1/2) * 4 + b --> 5 = -2 + b, b = 7.

Answer 2

the slope of the perpendicular line is -1/2

B = y - mx = 5 - (-1/2)(4) = 5 - -2 = 5 + 2 = 7

y = (-1/2)x + 7