Moderate -0.8 This is a straightforward discriminant question requiring students to recall that b²-4ac < 0 for no real roots, then solve the simple inequality 64-8a < 0 to get a > 8. It's slightly easier than average because it's a direct application of a standard technique with minimal algebraic manipulation.
Find the set of values of $a$ for which the equation
$$ax^2 + 8x + 2 = 0$$
has no real roots. [3]
\hfill \mbox{\textit{OCR MEI AS Paper 2 2018 Q5 [3]}}