AP EAMCET202423 May 2024Morning ShiftMathematicsStraight LinesActual
The origin is shifted to the point (2,3) by translation of axes and then the coordinate axes are rotated about the origin through an angle in the counter-clockwise sense. Due to this if the equation 3 x^2+2 x y+3 y^2-18 x-22 y+50=0 is transformed to 4 x^2+2 y^2-1=0 , then the angle =
Options
- A4
- B3
- C6
- D2
Correct answer
A. 4
Step-by-step solution
3 x^2+2 x y+3 y^2-18 x-22 y+50=0 Shifting origin to the point (2,3) , put x=X+2, y=Y+3 aligned & 3(X+2)^2+2(X+2)(Y+3)+3(Y+3)^2 & -18(X+2)-22(Y+3)+50=0 & 3 X^2+2 X Y+3 Y^2-1=0 aligned Now, for rotating about angle, put aligned & X=x^ -y^ and Y=x^ +y^ & 3 (x^ -y^ )^2+2 (x^ -y^ ) & (x^ +y^ )+3 (x^ +y^ )^2-1=0 & (3 ^2 +3 ^2 +2 ) x^ 2 & + (3 ^2 +3 ^2 -2 ) y¹² & + (2 ^2 -2 ^2 -6 . & +6 ) x^ y^ -1=0 & (3+ 2 ) x^ 2 +(3- 2 ) y^ 2 +(2 2 ) x^ y^ -1=0 aligned Comparing with 4 x^2+2 y^2-1=0 we get, 2 2 =0 = 4