1.

Number of real solutions of `sqrt(x)+sqrt(x-sqrt(1-x))=1` isA. `0`B. `1`C. `2`D. infinite

Answer» Correct Answer - B
`(b)` We have `sqrt(x)+sqrt(x-sqrt(1-x))=1`
`impliessqrt(x-sqrt(1-x))=1-sqrt(x)`
Squaring
`x-sqrt(1-x)=1+x-2sqrt(x)`
`implies2sqrt(x)-sqrt(1-x)=1` ..........`(i)`
`implies (2sqrt(x)-sqrt(1-x))(2sqrt(x)+sqrt(1-x))=(2sqrt(x)+sqrt(1-x))`
`implies4x-(1-x)=2sqrt(x)+sqrt(1-x)`
`implies 2sqrt(x)+sqrt(1-x)=5x-1` ................`(ii)`
Adding `(i)` and `(ii)`,
`4sqrt(x)=5x`
`implies 16x=25x^(2)`
`implies x=0,(16)/(25)`
Clearly `x=0` does not satisfy the equation.
Putting `x=(16)/(25)` in equation
`L.H.S=(4)/(3)+sqrt((16)/(25)-(3)/(5))=(4)/(5)+(1)/(5)=1`
So `x=(16)/(25)` is the only solution.


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