document.write( "Question 197635This question is from textbook Texas Edition McDougal Littell Algebra 2
\n" ); document.write( ": CHallenge: Under Certain conditions, the wind speed s (in knots) at an altitude of h meters above a grassy plain can be modeled by this function:
\n" ); document.write( " s(h)=2 ln (100h)
\n" ); document.write( "a. By what amount does the wind speed increase when the altitude doubles\r
\n" ); document.write( "\n" ); document.write( "b. Show that the given function can be written in terms of common logarithms as s(h)=2/loge (log h+2)\r
\n" ); document.write( "\n" ); document.write( "umm on a , so far I got change in altitude=s(2h)-s(h)
\n" ); document.write( "then 2ln(100(2h))-2ln(100h) then idk\r
\n" ); document.write( "\n" ); document.write( "on b, i'm not quite sure what to do,
\n" ); document.write( "

Algebra.Com's Answer #148198 by jim_thompson5910(35256)\"\" \"About 
You can put this solution on YOUR website!
a)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%28h%29=2%2Aln%28100h%29\" Start with the given equation.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%282h%29=2%2Aln%28100%282h%29%29\" Replace \"h\" with \"2h\" (since the altitude doubles)\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%282h%29=2%2Aln%282%2A100h%29\" Rearrange the terms.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%282h%29=2%28ln%282%29%2Bln%28100h%29%29\" Expand the log using the identity \"ln%28A%2AB%29=ln%28A%29%2Bln%28B%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%282h%29=2%2Aln%282%29%2B2%2Aln%28100h%29\" Distribute\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%282h%29=2%2Aln%282%29%2Bs%28h%29\" Replace \"2%2Aln%28100h%29\" with \"s%28h%29\". Note: this can be done since \"s%28h%29=2%2Aln%28100h%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%282h%29=ln%282%5E2%29%2Bs%28h%29\" Rewrite the log using the identity \"y%2Aln%28x%29=ln%28x%5Ey%29\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%282h%29=ln%284%29%2Bs%28h%29\" Square 2 to get 4\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "So when the altitude doubles, the speed of the wind increases by \"ln%284%29\" knots. Since , this means that the speed of the wind increases by about 1.38629 knots.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "---------------------------------------------------------------------\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "b)\r
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Are you only supposed to convert to a common log? If so, then there's not much to this part...\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%28h%29=2%2Aln%28100h%29\" Start with the given equation.\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%28h%29=2%2Alog%28e%2C%28100h%29%29\" Convert to a standard log of base \"e\"\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "\"s%28h%29=2%2A%28log%2810%2C%28100h%29%29%2Flog%2810%2C%28e%29%29%29\" Now use the change of base formula (this step may be optional)\r
\n" ); document.write( "
\n" ); document.write( "
\n" ); document.write( "\n" ); document.write( "Remember the change of base formula is \"log%28b%2C%28x%29%29=log%2810%2C%28x%29%29%2Flog%2810%2C%28b%29%29\"
\n" ); document.write( "
\n" ); document.write( "
\n" );