If there is exactly one root of the equation 2x^2 + ax + b, where a and b are positive constants, what is b in terms of a? Choose one:
A) a/2  B) a  C) 3a/2  D) a^2/8  E) a^2/4
one root for a quadratic equation ax^2+bx+c is possible only when b^2 = 4ac ---1   Here b = a   c= b   a = 2   substituting these values in 1, we have   a^2 = 8b =&gt; b =a^2/8   Answer is a^2/8.
<result>D</result>
If there is exactly one root of the equation 2x^2 + ax + b, where a and b are positive constants, what is b in terms of a?