document.write( "Question 29292: Show that 1/sqrt 1 + 1/sqrt 2 + 1/sqrt 3...+ 1/sqrt n < 2*sqrt n for all positive integers. \n" ); document.write( "
Algebra.Com's Answer #16146 by venugopalramana(3286)\"\" \"About 
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Show that 1/sqrt 1 + 1/sqrt 2 + 1/sqrt 3...+ 1/sqrt n < 2*sqrt n for all positive integers.
\n" ); document.write( "COSIDER THE EQN.
\n" ); document.write( "SQRT(N+1)-SQRT(N)={SQRT(N+1)-SQRT(N)}*{SQRT(N+1)+SQRT(N)/{SQRT(N+1)+SQRT(N)}
\n" ); document.write( "={(N+1)-(N)}/{SQRT(N+1)+SQRT(N)}=1 / {SQRT(N+1)+SQRT(N)}>1 / {SQRT(N+1)+SQRT(N+1)}
\n" ); document.write( "=1 / 2*SQRT(N+1)...HENCE
\n" ); document.write( "SQRT(N+1)-SQRT(N) > 1/2*SQRT(N+1)..PUT N=1,2,3...N..IN THIS EQN. AND ADD UP...
\n" ); document.write( "N=1...............SQRT2-SQRT1>1/2SQRT2
\n" ); document.write( "N=2...............SQRT3-SQRT2>1/2SQRT3
\n" ); document.write( "N=3...............SQRT4-SQRT3>1/2SQRT4
\n" ); document.write( "......................................
\n" ); document.write( ".......................................
\n" ); document.write( "N=N-1.............SQRT(N)-SQRT(N-1)>1/2SQRT(N)
\n" ); document.write( "N=N...............SQRT(N+1)-SQRT(N)>1/2SQRT(N+1)
\n" ); document.write( "-------------------------------------------------ADDING.....
\n" ); document.write( "WE FIND ALL TERMS ON LHS CANCEL EXCEPT
\n" ); document.write( "SQRT(N+1)-SQRT(1)>(1/2){ 1/sqrt 2 + 1/sqrt 3...+ 1/sqrt n }
\n" ); document.write( "OR.... \r
\n" ); document.write( "\n" ); document.write( "{1/sqrt 1 + 1/sqrt 2 + 1/sqrt 3...+ 1/sqrt n } > 2*{SQRT(N+1)-SQRT(1)}+1/SQRT1
\n" ); document.write( "=2SQRT(N+1)-1>2SQRT(N+1)>2SQRT(N) \r
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