document.write( "Question 1090501: hi can somebody please help me with this question?
\n" ); document.write( "for what value(s) of k will the function g(x)=x^2+kx+1 have only one zero
\n" ); document.write( "A.0
\n" ); document.write( "B.2
\n" ); document.write( "C.-2,2
\n" ); document.write( "D. no values will work.
\n" ); document.write( "Thank you so much. \n" ); document.write( "

Algebra.Com's Answer #704943 by greenestamps(13200) $\"\"$ $\"About$

You can put this solution on YOUR website!

In the quadratic formula, the discriminant, b^2-4ac, tells you whether the quadratic expression has two, one, or no real zeros. If the discriminant is positive, there are two zeros; if it is 0, there is one zero (a double root); if it is negative, there are no real zeros.

\n" ); document.write( "So in your example, there is only one zero if the discriminant is zero:
\n" ); document.write( " $\"b%5E2-4ac+=+k%5E2-4%281%29%281%29+=+k%5E2-4+=+0\"$
\n" ); document.write( " $\"k%5E2-4+=+0\"$
\n" ); document.write( " $\"%28k%2B2%29%28k-2%29+=+0\"$

\n" ); document.write( "The values -2 and 2 each make the discriminant equal to 0.

\n" ); document.write( "So answer C, -2 and 2. \n" ); document.write( "

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