Question

The equation of the latus rectum of a parabola is x + y = 8 and the equation of tangent at the vertex is x + y = 12 then the length of the latus reactum is

• A. $4 \sqrt { 2 }$unit
• B. $2 \sqrt { 2 }$unit
• C. 8 unit
• D. $8 \sqrt { 2 }$ unit

Answer 1

Answer: (D)

$8 \sqrt { 2 }$ unit

Answer 2

Since the equation of latus rectum and equation of tangent both are parallel and they lies in the same side of the of origin

\ distance b/w then is

\ length of latus rectum = 4a = $4 ( 2 \sqrt { 2 } ) = 8 \sqrt { 2 }$