document.write( "Question 265813: Can you explain what the i in a complex number stands for and why it is necessary in some problems?\r
\n" ); document.write( "\n" ); document.write( "Also, can you explain the procedures of completing the square of a quadratic equation \n" ); document.write( "
Algebra.Com's Answer #195385 by stanbon(75887)\"\" \"About 
You can put this solution on YOUR website!
x^2+1 = 0 has no solution in the real number system.
\n" ); document.write( "If x^2 = -1
\n" ); document.write( "x = +-i
\n" ); document.write( "----
\n" ); document.write( "So \"i\" is one solution for the equation x^2+1 = 0
\n" ); document.write( "But (sqrt(-1))^2 = -1
\n" ); document.write( "So (sqrt(-1))^2 + 1 = 0
\n" ); document.write( "Therefore sqrt(-1) = i
\n" ); document.write( "-------------------------
\n" ); document.write( "For more on this subject use Google and
\n" ); document.write( "search for complex numbers.
\n" ); document.write( "===================================
\n" ); document.write( "Completing the Square.
\n" ); document.write( "I would suggest you post one or two of the
\n" ); document.write( "problems you are having with this topic
\n" ); document.write( "as there are different ways of handling
\n" ); document.write( "simple and complex cases.
\n" ); document.write( "Cheers,
\n" ); document.write( "Stan H. \n" ); document.write( "
\n" );