document.write( "<A HREF=/cgi-bin/jump-to-question.mpl?question=1164875>Question 1164875</A>: <I><SPAN STYLE=\"word-break: break-all;\"> Find the equation for an exponential function that passes through the pair of points given below. (Round all coefficients to 4 decimal places when necessary.) HINT [See Example 2.]<BR>\n" );
document.write( "Through (2, 18) and (4, 162)\r<BR>\n" );
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document.write( "f(x) = <BR>\n" );
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document.write( "</I><HR><TABLE width=100%><TR><TD><B><A HREF=http://www.algebra.com/>Algebra.Com's</A> Answer #789299 by </B><A HREF=/tutors/aboutme.mpl?userid=Boreal><B>Boreal(15235)</B></A><img src=\"/images/stars/stars-13.gif\" alt=\"\" >&nbsp;<A HREF=/tutors/aboutme.mpl?userid=Boreal><IMG SRC=http://www.algebra.com/images/aboutme-small.gif BORDER=0 alt=\"About Me\" VALIGN=MIDDLE></A>&nbsp;<IMG SRC=http://www.algebra.com/cgi-bin/show-face.mpl?user=Boreal><BR>You can <A HREF=\"/cgi-bin/embed-solution.mpl?show=1&solution=789299\">put this solution on YOUR website!</A><BR><SPAN STYLE=\"word-break: break-all;\"> f(x)=ab^x<BR>\n" );
document.write( "18=ab^2<BR>\n" );
document.write( "162=ab^4<BR>\n" );
document.write( "so b^2=18/a<BR>\n" );
document.write( "and therefore b^4=324/a^2<BR>\n" );
document.write( "162 = 324/a<BR>\n" );
document.write( "a=2\r<BR>\n" );
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document.write( "if a=2 then 18=2b^2 and b^2=9 and b=3<BR>\n" );
document.write( "check with a=4 and 162=2*81=162 checks\r<BR>\n" );
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document.write( "the equation is f(x)=2*3^x<BR>\n" );
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