1) A straight line makes an intercept on the Y-axis twice as long as that on X-axis and is at unit distance from the origin. Then the line is represented by the equations, A) 2x+3y=±√5 B) x+y=±2 C) x+y=±2 D) 2x+y=±√5 Answer: Option DExplanation:Let equation of line be xa+y2a=1 ⇒ =2x+y=2a Distance from origin is |2a√(2)2+(1)2|=|2a√5| ⇒ |2a√5|=1 ⇒2a=±√5 Hence , equation of line is 2x+y=±√5