document.write( "Question 99359: Evaluate log6 (36) without using your calculator. \n" ); document.write( "
Algebra.Com's Answer #72270 by bucky(2189)\"\" \"About 
You can put this solution on YOUR website!
Given:
\n" ); document.write( ".
\n" ); document.write( "\"log%286%2C36%29\"
\n" ); document.write( ".
\n" ); document.write( "To evaluate this, let's say that it equals y. So we write the problem as:
\n" ); document.write( ".
\n" ); document.write( "\"log%286%2C36%29+=+y\"
\n" ); document.write( ".
\n" ); document.write( "In your head, you can change this to exponential form by raising the base 6 to the y power and
\n" ); document.write( "setting it equal to 36. In equation form this is:
\n" ); document.write( ".
\n" ); document.write( "\"6%5Ey+=+36\"
\n" ); document.write( ".
\n" ); document.write( "But you can recognize that 36 is equal to \"6%5E2\". So substitute this for 36 and the equation
\n" ); document.write( "becomes:
\n" ); document.write( ".
\n" ); document.write( "\"6%5Ey+=+6%5E2\"
\n" ); document.write( ".
\n" ); document.write( "Now notice that on both sides of this equation the base number is 6 and it is raised to
\n" ); document.write( "a power. Since the power is 2 on one side and y on the other side, the value of y has to
\n" ); document.write( "be 2 if both sides are equal. Therefore, you have found that y must be equal to 2.
\n" ); document.write( ".
\n" ); document.write( "Next recall that way back at the beginning we said that:
\n" ); document.write( ".
\n" ); document.write( "\"log%286%2C36%29+=+y\"
\n" ); document.write( ".
\n" ); document.write( "So you can substitute 2 for y and get the answer:
\n" ); document.write( ".
\n" ); document.write( "\"log%286%2C36%29+=+2\"
\n" ); document.write( ".
\n" ); document.write( "Hope this helps you to see how you can do the problem without using a calculator.
\n" ); document.write( "(Most calculators don't work for logarithm bases other than 10 or e anyhow unless you
\n" ); document.write( "use a formula known as the \"change of base formula.\")
\n" ); document.write( ".
\n" ); document.write( "The technique for changing from logarithmic form to exponential form is very useful in
\n" ); document.write( "solving many logarithmic problems. You should become proficient in using it.
\n" ); document.write( ".
\n" ); document.write( "
\n" ); document.write( "
\n" );