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COMEDK2020MathematicsCircle

If 3 x+y+k=0 is a tangent to the circle x²+y²=10 , the values of k are

Options

  1. A5
  2. B7
  3. C9
  4. D10

Correct answer

D. 10

Step-by-step solution

We have, 3 x+y+k=0 is iargent to the circle x²+v²=10 . So, distance of line 3 x+y+k=0 from centre of the circle will he equal to the radius of circle. aligned & 3(0)+(0)+K (3)²+(1)² = 10 & K 10 = 10 K= 10 aligned

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