NTA Abhyas 2020
- Exam
- NTA Abhyas
- Year
- 2020
- Subject
- Mathematics
- Chapter
- Ellipse
NTA Abhyas 2020 · Mathematics · Ellipse
A tangent having slope& - (4)/(3) to the ellipse x^ 2 18 + y^ 2 32...
A tangent having slope& to the ellipse intersects the major and minor axes at and . If is the origin, then the area of is
Options
- A
- B
- C
- D
Correct answer
C.
Step-by-step solution
Any point on the ellipse can be taken as \left(3\sqrt{2}cos \theta,sin \theta\right)- = - \dfrac{32 \lleft(3\sqrt{2}cos \theta)}{18 \lsin } = cot \theta \ldots . \left(1\right)= - \left(2\right)
From equations (1) and (2), we get,~
\theta =\theta = \dfrac{\pi}{4}
Hence, the equation of the tangent is \dfrac{x . \dfrac{1}{\sqrt{2}}}{3\sqrt{2}} + \dfrac{y . \dfrac{1}{\sqrt{2}}}{4\sqrt{2}} =
(i.e.) \dfrac{x}{6} + \dfrac{y}{8} =~
Hence,& A = \left(6, 0\right), B = \left(0, 8\right)\Delta OAB = \dfrac{1}{2} \times6 \times8 = 24sq . units
From equations (1) and (2), we get,~
\theta =\theta = \dfrac{\pi}{4}
Hence, the equation of the tangent is \dfrac{x . \dfrac{1}{\sqrt{2}}}{3\sqrt{2}} + \dfrac{y . \dfrac{1}{\sqrt{2}}}{4\sqrt{2}} =
(i.e.) \dfrac{x}{6} + \dfrac{y}{8} =~
Hence,& A = \left(6, 0\right), B = \left(0, 8\right)\Delta OAB = \dfrac{1}{2} \times6 \times8 = 24sq . units