document.write( "Question 62071: I'm having a hard enough time in Algebra - now they want me to deal with \"imaginary\" numbers? I'm having trouble with simplifying (using i):\r
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document.write( "sqrt(-8) + sqrt(-50)\r
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document.write( "can someone help, please? \n" );
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Algebra.Com's Answer #42835 by ptaylor(2198)![]() ![]() You can put this solution on YOUR website! I'll Try.\r \n" ); document.write( "\n" ); document.write( "You know that the sqrt of a number is another number that, when multiplied by itself, yields the original number. For example, the sqrt of 9 is plus 3 or minus 3 since minus times minus equals a plus. Now, lets look at the sqrt \n" ); document.write( "of -9. Clearly, there are no real numbers that can be multiplied by themselves to yield a -9. Thus, the definition \"sqrt(-1)=i\" and i is defined as an imaginary number. \r \n" ); document.write( "\n" ); document.write( "Now we also know that the sqrt (-8) is equal to the sqrt (-1) times sqrt(8) which also equals sqrt(-1) times sqrt (4) times sqrt(2). simplifying: \n" ); document.write( "sqrt (-1)=i \n" ); document.write( "sqrt (4)=2 \n" ); document.write( "sqrt2=sqrt2\r \n" ); document.write( "\n" ); document.write( "we now have: \n" ); document.write( "sqrt(-8)=(2i)(sqrt (2)) \r \n" ); document.write( "\n" ); document.write( "Likewise sqrt (-50) equals sqrt (-1) times sqrt (50) which also equals sqrt (-1) times sqrt (2) times sqrt (25). simplifying, we have \n" ); document.write( "sqrt (-1)=i \n" ); document.write( "sqrt (25)=5 \n" ); document.write( "sqrt (2)=sqrt (2)\r \n" ); document.write( "\n" ); document.write( "We now have: \n" ); document.write( "sqrt(-50)=(5i)(sqrt(2)) Finally:\r \n" ); document.write( "\n" ); document.write( "sqrt(-8)+sqrt(-50)= (2i)(sqrt(2))+(5i)(sqrt(2)) which equals \n" ); document.write( "(sqrt(2))(5i+2i)=(7i)(sqrt(2))\r \n" ); document.write( "\n" ); document.write( "Hope this helps. I know it does get confusing sometimes ----ptaylor\r \n" ); document.write( " \n" ); document.write( "\n" ); document.write( " \n" ); document.write( " |