Number of tangents that can be drawn from a point to a circle or ellipse or hyperbola or parabola
Steps:
- Copy question on calculator making right side as zero.
- Put given values of (x,y) pressing CALC button on calculator.
- You will have three conditions then:
- If you get answer in negative (-something). The point is lies inside the conic. So, you will have no tangents can be drawn from that point.
- If you get answer as 0. The point lies at the locus of the conic. So You will have only 1(one) tangent.
- If you get positive answer. The points lies outside the conic. So, you will have 2(two) tangent that can be drawn to the conic.
4. Watch the above video for the detail explanation.
5. This method also works for parabola too.