1.

Number of integral values of 'a' for which (a-5)x^2 - 2ax + (a-4)=0 , has exactly one root in(0, 2), is

Answer»

18
20
19
Infinite

Solution :`(a-5)X^2-2ax+(a-4)=0`
ROOTS lies in the INTERVAL (0,2)
f(2)=4a -20-4a+a-4=(a-24)
f(0).f(2) lt 0
(a-4)(a-24) lt 0
a `in`(4,24 )
For a=4
`-x^2-8x=0`
`x(x+8)=0 rArr r=0,-8`
So a=4 is not possible
For a=24
`19x^2 -48x +20=0`
`19x^2 -38x -10x +20=0`
(x-2)(19x-10)=0
`x=2,10/19`
So , a =24 is possible
so, a `in` (4,24)


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