ExamBro
ExamBro
TS EAMCET · Maths · Straight Lines

When the coordinate axes are rotated through an angle \(\theta\) in anti clockwise direction, if the transformed equation of \(x^2+y^2+2 x y+2 x+6 y+1=0\) is \((2+\sqrt{3}) X^2+2 X Y+(2-\sqrt{3}) Y^2+a X+b Y+2=0\) then \(3 a-b=\)

  1. A 10
  2. B \(2(1+2 \sqrt{3})\)
  3. C 20
  4. D \(2(3+\sqrt{3})\)
Verified Solution

Answer & Solution

Correct Answer

(C) 20

Step-by-step Solution

Detailed explanation

If coordinate axes are rotated through an angle \(\theta\) in anti-clockwise direction, then \(x=X \cos \theta-Y \sin \theta\) and \(y=X \sin \theta+Y \cos \theta\), on substituting the values of \(x\) and \(y\) in equation \(x^2+y^2+2 x y+2 x+6 y+1=0 \text {, we get }\)…