(c) In a trisection of lines in quadrant, angle 90° is divided into three parts and each part contain 30°, as shown in figure ∴ Equation of line OB is y=tan30°x ⇒ y=
1
√3
x x−√3y=0 And equation of line OC is y=tan60°x ⇒ y=√3x(√3x−y)=0 ∴ Their combined equation is (x−√3y)(√3x−y)=0 ⇒ √3x2−xy - 3xy+√3y2=0 ⇒ √3x2−4xy + √3y2=0