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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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