Maths-
General
Easy
Question
The parametric representation of a parabola is x = 3 + t2, y = 2t – 1. Its focus is -
- (3, – 1)
- (3, 0)
- (4, 0)
- (4, –1)
The correct answer is: (4, –1)
x = 3 + t2 
y = 2t – 1
t2 = x – 3 (y + 1) / 2 = t (y + 1)2 = 4(x – 3)
Y2 = 4X focus X = 1, Y = 0
x – 3 = 1, y + 1 = 0 x = 4, y = – 1 (4, –1)
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