Q.

A chord of the circle x2+y2-4x-6y=0 passing through origin subtends an angle tan-1(74) at the point where the circle meets positive y-axis, then equation of the chord is

1 2x+3y=0  
2 x+2y=0  
3 x-2y=0  
4 2x-3y=0  

Ans.

(3)

Equation of tangent at origin is

-2(x+0)-3(y+0)=0⇒2x+3y=0

tanθ=74⇒|m+231-2m3|=74⇒3m+23-2m=74

⇒12m+8=21-14m⇒26m=13⇒m=12

∴  y=12x⇒x-2y=0