WBJEE · Maths · Parabola
The equation of the latus rectum of a parabola is \(x+y=8\) and the equation of the tangent at the vertex is \(x+y=12\). Then the length of the latus rectum is
- A \(4 \sqrt{2}\) unit
- B \(2 \sqrt{2}\) unit
- C 8 unit
- D \(8 \sqrt{2}\) unit
Answer & Solution
Correct Answer
(D) \(8 \sqrt{2}\) unit
Step-by-step Solution
Detailed explanation
Hint: The distance between latus rectum and equation of tangent at vertex is 'a'. Here \(\mathrm{a}=\frac{4}{\sqrt{1+1}}=2 \sqrt{2}\) So, length of latus rectum \(=4 \mathrm{a}=8 \sqrt{2}\) unit
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