Question

If the lines joining the origin to the points of intersection of the line 3y = mx + 3 and the curve x² + y² = 1 are at right angle, then value of m + 3 is equal to

(A) 5

(B)  6 

(C)  1 

(D)  Zero

Answer 1

Correct option (b) (d) 

 See Fig.

⇒ 9 + m² = 18

⇒ m² = 9

⇒ m = ± 3

⇒ m + 3 = 6, 0