1.

Consider the parabola x^(2) +4y = 0. Let P(a,b) be any fixed point inside the parabola and let S be the focus of the parabola. Then the minimum value at SQ +PQ as point Q moves on the parabola is

Answer»

`|1 -a|`
`|ab|+1`
`SQRT(a^(2)+b^(2))`
`1-b`

Solution :
Let the foot of perpendicular from Q to the directrix be N.
`SQ + PQ = QN + PQ` is minimum when P, Q and N are COLLINEAR. So, minimum value of `SQ + PQ = PN = 1 -b`


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