AP EAMCET201823 Apr 2018Evening ShiftMathematicsStraight LinesActual
The transformed equation of 3 x^2-6 x y+8 y^2=8 when the axes are rotated about the origin through an angle 4 in the positive direction, is
Options
- A5 x^2+10 x y+17 y^2+16=0
- B5 x^2+10 x y+17 y^2-16=0
- C5 x^2-10 x y+17 y^2-16=0
- D5 x^2-10 x y+17 y^2+16=0
Correct answer
B. 5 x^2+10 x y+17 y^2-16=0
Step-by-step solution
Given transformed equation is 3 x^2-6 x y+8 y^2=8 Now, x^ =x 4 -y 4 = x-y 2 and y^ =x 4 +y 4 = x+y 2 Before transformation the equation is aligned & 3 ( x-y 2 )^2-6 ( x-y 2 ) ( x+y 2 )+8 ( x+y 2 )^2=8 & 3 (x^2+y^2-2 x y )-6 (x^2-y^2 ) & +8 (x^2+y^2+2 x y )=16 & 5 x^2+17 y^2+10 x y-16=0 . aligned