1.

The straight line y = a – x touches the parabola x2 = x – y if a = .......

Answer»

line: y = a – x 

Parabola: y = x – x2 

∴ a – x = x – x2 

∴         x2 – 2x + a = 0 

∵ line touches the parabola, roots should be equal. 

∴    B2 – 4AC = (– 2)2 – 4(1)(a) = 0 

∴     4 = 4a 

i.e.   a = 1.



Discussion

No Comment Found

Related InterviewSolutions