NTA Abhyas 2020
- Exam
- NTA Abhyas
- Year
- 2020
- Subject
- Mathematics
- Chapter
- Hyperbola
NTA Abhyas 2020 · Mathematics · Hyperbola
Two straight lines having variable slopes m _ 1 ~and& m _ 2 pass...
Two straight lines having variable slopes ~and& pass through the fixed points~\left(a, 0\right)~and& \left(- a, 0\right) respectively. If , then the eccentricity of the locus of the point of intersection of the lines is
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
Let, the lines are and y = {m}_{2} \left(x + a\right)
& k = {m}_{2} \left( h + a\right)⇒ k^{2} = {m}_{1}{m}_{2} \left(h^{2} - a^{2}\right)
\dfrac{k^{2}}{2} = h^{2} - a^{2}(given,&{m}_{1}{m}_{2} = 2⇒ \dfrac{x^{2}}{1} - \dfrac{y^{2}}{2} = a^{2}= \sqrt{1 + \dfrac{2}{1}} = \sqrt{3}
& k = {m}_{2} \left( h + a\right)⇒ k^{2} = {m}_{1}{m}_{2} \left(h^{2} - a^{2}\right)
\dfrac{k^{2}}{2} = h^{2} - a^{2}(given,&{m}_{1}{m}_{2} = 2⇒ \dfrac{x^{2}}{1} - \dfrac{y^{2}}{2} = a^{2}= \sqrt{1 + \dfrac{2}{1}} = \sqrt{3}