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The number of real roots of the equation `sqrt(1+sqrt(5)x+5x^(2))+sqrt(1-sqrt(5)x+5x^(2))=4` is |
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Answer» Correct Answer - C We have, `sqrt(1+sqrt(5)x+5x^(2))+sqrt(1-sqrt(5)x+5x^(2))=4 " "`………(i) Also, `(1+sqrt(5)x+5x^(2))-(1-sqrt(5)x+5x^(2))=2sqrt(5)x " "`........(ii) Dividing (ii) by (i), we get `:. sqrt(1+sqrt(5)x+5x^(2))-sqrt(1-sqrt(5)x+5x^(2))=(sqrt(5))/(2)x " "`.......(iii) Adding (i) and (iii), we get `sqrt(1+sqrt(5)x+5x^(2))=2+(sqrt(5))/(4)x` `implies 1+sqrt(5)x+5x^(2)=4+(5)/(16)x^(2)+sqrt(5)x` `implies x^(2)=(16)/(25) impliesx=+-(4)/(5)` |
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