JEE Main 2019 Mathematics question
If the tangents on the ellipse at the points (1, 2) and (a, b) are perpendicular to each other, then is equal to:
Answer: (A)
Solution
Slopes −2 and −4a/b; product −1 ⇒ b = −8a; ⇒ .
If the tangents on the ellipse at the points (1, 2) and (a, b) are perpendicular to each other, then is equal to:
Slopes −2 and −4a/b; product −1 ⇒ b = −8a; ⇒ .