document.write( "Question 146485: Invisible numbers...Perform indicated operation. Write results in the form of a+bi\r
\n" );
document.write( "\n" );
document.write( "6 / 5-2i\r
\n" );
document.write( "\n" );
document.write( "Six divided by five minus 2i. \r
\n" );
document.write( "\n" );
document.write( "I started this problem by mutiplying the numerator and the denominator by five minus 2i. I obtained the answer of 30 -12i for the numerator...and I do not know what to do after that.\r
\n" );
document.write( "\n" );
document.write( "Thanks! \n" );
document.write( "
Algebra.Com's Answer #106916 by nerdybill(7384)![]() ![]() You can put this solution on YOUR website! The whole idea is to get rid of any i's you see in the denominator. How do we do this? \n" ); document.write( "Since we know that i*i = -1 \n" ); document.write( "We would like to apply this bit of info. \n" ); document.write( "We need to find something to multiply the denominator such that we can rid ourselves of that i. \n" ); document.write( ". \n" ); document.write( "So, if you started with: \n" ); document.write( ". \n" ); document.write( "6/(5-2i) \n" ); document.write( ". \n" ); document.write( "Multiply numerator and denominator with (5+2i) \n" ); document.write( "6/(5-2i) * (5+2i)/(5+2i) \n" ); document.write( ". \n" ); document.write( "Looking at the denominator, we have: \n" ); document.write( " (5-2i)(5+2i) \n" ); document.write( "Applying \"FOIL\", we get (25 + 10i - 10i + 4) \n" ); document.write( "notice the i's go away leaving just 29. \n" ); document.write( ". \n" ); document.write( "So, let's multiply out: \n" ); document.write( "6/(5-2i) * (5+2i)/(5+2i) \n" ); document.write( ". \n" ); document.write( "we get: \n" ); document.write( "6(5+2i)/29 \n" ); document.write( ". \n" ); document.write( "(30+12i)/29 \r \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |