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Magical Mathematics[Interesting Approach]

find the value of x for which [x]+[x]^2>25

Profile image of AMIT KUMAR PURAN
16 Years agoGrade
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1 Answer

Profile image of Askiitians Expert Mohit Singla
16 Years ago

Dear Amit,

Let [x] =y

Please specify whether [x] is the greatest integer function or not.

y^2+y-25>0

or {y-({-1+(101)^1/2}/2)}{y-({-1-(101)^1/2}/2)}>0

(y-4.5)(y+5.2)>0

or -infinity<y<-5.2 and 4.5<y<infinity.

But y=[x]

If [x] is the greatest integer function then

So x≤-6 and x≥5 is the solution.

 

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