UPSC NDA Math Model Paper 2

Given: 3x + y = 3
⇒ y = -3x + 3
The slope of line = m = -3
Then the slope of a line perpendicular to it is -1/m = 1/3
The equation of line passing through (2, 2) with slope "1/3" is
y - 2 = (1/3) (x - 2)
⇒ 3y - 6 = x - 2
⇒ 3y = x + 4
⇒y=

1

3

x+

4

3

So, the y-intercept of line is 4/3