document.write( "Question 952164: Prove that the roots of 2x^2+8x+5 are real and irrational \n" ); document.write( "

Algebra.Com's Answer #581495 by Theo(13342) $\"\"$ $\"About$

You can put this solution on YOUR website!
look at the discriminant.
\n" ); document.write( "a = 2
\n" ); document.write( "b = 8
\n" ); document.write( "c = 5
\n" ); document.write( "b^2 - 4ac = 64 - 4*2*5 = 64 - 40 = 24
\n" ); document.write( "24 is positive and not a perfect square so the roots are real and irrational.
\n" ); document.write( "in order for the roots to be real and rational, the discriminant has to be positive and has to be a perfect square.
\n" ); document.write( "a perfect square is when the square root of a number is an integer.
\n" ); document.write( "sqrt(24) is not an integer.
\n" ); document.write( "but it is positive.
\n" ); document.write( " \n" ); document.write( "

\n" );