Question:
The roots of the equation $2 x^{2}-6 x+7=0$ are
(a) real, unequal and rational
(b) real, unequal and irrational
(c) real and equal
(d) imaginary
Solution:
(d) imaginary
$\because D=\left(b^{2}-4 a c\right)$
$=(-6)^{2}-4 \times 2 \times 7$
$=36-56$
$=-20<0$
Thus, the roots of the equation are imaginary.