AP EAMCET20224 Jul 2022Morning ShiftMathematicsCircleActual
For any two nonzero real numbers a and b if this line x a + y b = 1 is a tangent to the circle x 2 + y 2 = 1 , then which of the following is true?
Options
- A1 a , 1 b lies inside the circle
- Ba , b lies inside the circle
- C1 a , 1 b lies on the circle
- Da ,   b lies on the circle
Correct answer
C. 1 a , 1 b lies on the circle
Step-by-step solution
Given, Equation of circle as x 2 + y 2 = 1 , Now assuming a point x 1 , y 1 on circle we have equation of tangent at this point given by x x 1 + y y 1 = 1   . . . . . . . . . . . . . . . 1 , Now given x a + y b = 1 is tangent to the given circle so on comparing with equation 1 we get, x 1 = 1 a   &   y 1 = 1 b So point lie on the circle.