When the coordinate axes are rotated through an angle $\frac{\pi}{4}$ in the positive direction, an equation…

When the coordinate axes are rotated through an angle $\frac{\pi}{4}$ in the positive direction, an equation is transformed to $x^2+y^2-6 x+8 y+21=0$. Then that original equation is
  1. $x^2+y^2-7 \sqrt{2} x+\sqrt{2} y+21=0$
  2. $\sqrt{2} x^2+\sqrt{2} y^2-7 x+y+21 \sqrt{2}=0$
  3. $x^2+y^2-14 x+2 y+21=0$
  4. $x^2+y^2-7 \sqrt{2} x+\sqrt{2} y+21 \sqrt{2}=0$

Solution

No solution. Refer to answer key.

Asked in: AP EAMCET 2017 (26 Apr Shift 2)

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