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2x2 – 9x + 2 = –1

The discriminant is less than 0, so there are two real roots.
The discriminant is less than 0, so there are two complex roots.
The discriminant is greater than 0, so there are two real roots.
The discriminant is greater than 0, so there are two complex roots.

User Munish
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1 Answer

7 votes

Answer:

C) The discriminant is greater than 0, so there are two real roots

Explanation:

Discriminant


b^2-4ac\quad\textsf{when}\:ax^2+bx+c=0


\textsf{when }\:b^2-4ac > 0 \implies \textsf{two real roots}


\textsf{when }\:b^2-4ac=0 \implies \textsf{one real root}


\textsf{when }\:b^2-4ac < 0 \implies \textsf{no real roots}


2x^2-9x+2=-1


\implies 2x^2-9x+3=0


\implies a=2, b=-9, c=3


\begin{aligned}b^2-4ac &amp;=(-9)^2-4(2)(3)\\&amp; =81-24\\&amp;=57 > 0\implies \textsf{two real roots}\end{aligned}

User Mercutio
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