Question

What is the equation of the line passing through (2, –3) and parallel to the y-axis ?

(a) y = –3 

(b) y = 2 

(c) x = 2 

(d) x = – 3

Answer 1

(c) x = 2 

Slope of y-axis = tan 90º                    (∵ y-axis ⊥ x-axis) 

∴ Equation of line passing through (2, –3) parallel to y-axis is (y + 3) = tan 90º (x – 2) 

⇒ (y + 3) = ∞ (x – 2) ⇒ (x – 2) = \(\frac{1}{\infty}\) (y + 3) = 0 ⇒ x = 2.