document.write( "Question 598014: How many years does it take for an investment to double in value if it is invested at 6%
\n" ); document.write( "if interest is compounded quarterly?\r
\n" ); document.write( "\n" ); document.write( "if interest is compounded continuously?
\n" ); document.write( "thanks
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Algebra.Com's Answer #378425 by lwsshak3(11628)\"\" \"About 
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How many years does it take for an investment to double in value if it is invested at 6%
\n" ); document.write( "if interest is compounded quarterly?
\n" ); document.write( "if interest is compounded continuously?
\n" ); document.write( "**
\n" ); document.write( "compound interest formula: A=P(1+r)^t, P=initial investment, r=interest rate per period, t=number of periods, A=amount after t periods.
\n" ); document.write( "For continuous compounding: A=Pe^rt
\n" ); document.write( "..
\n" ); document.write( "Quarterly compounding: A/P=2, r=.06/4=.015, t=quarters
\n" ); document.write( "A=P(1+r)^t
\n" ); document.write( "A/P=(1+.06/4)^t
\n" ); document.write( "A/P=(1+.015)^t
\n" ); document.write( "2=(1.015)^t
\n" ); document.write( "take log of both sides
\n" ); document.write( "log(2)=t*log(1.015)
\n" ); document.write( "t=log(2)/log(1.015)
\n" ); document.write( "t≈46.55 qtrs≈11.64 years
\n" ); document.write( "..
\n" ); document.write( "Continuous compounding: A/P=2, r=.06, t=years
\n" ); document.write( "A=Pe^rt
\n" ); document.write( "A/P=e^rt
\n" ); document.write( "2=e^rt
\n" ); document.write( "2=e^.06t
\n" ); document.write( "take log of both sides
\n" ); document.write( "ln2=.06t*lne
\n" ); document.write( "lne=1
\n" ); document.write( ".06t=ln2
\n" ); document.write( "t=ln2/.06
\n" ); document.write( "t≈11.55 years
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