Question

How do you write an equation of a line perpendicular to y=3+2x, passing through (4, -1)?

Answer 1

`x+2y=2`

Explanation:

Given line is y = 2x + 3. Its slope = 2

Let m be the slope of required line .
Then `mxx2 = - 1`. So, m = - 1/2

Let the required equation be `y = - 1/2 x +c`

Since it passes through (4,-1), we get
`- 1 = - 1/2xx4 +c or c = 1`

Hence the equation is `y = - 1/2 x+1`

`rArr x+2y = 2`