| Exam Board | WJEC |
|---|---|
| Module | Unit 1 (Unit 1) |
| Year | 2022 |
| Session | June |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Discriminant and conditions for roots |
| Type | Find range for no real roots |
| Difficulty | Standard +0.3 This is a standard discriminant problem requiring students to set b²-4ac < 0 for no real roots, leading to the inequality 4k²-32k < 0, which factors to k(k-8) < 0, giving 0 < k < 8. While it involves multiple algebraic steps and inequality manipulation, it's a routine application of a well-practiced technique with no novel insight required, making it slightly easier than average. |
| Spec | 1.02d Quadratic functions: graphs and discriminant conditions |
Find the range of values of $k$ for which the quadratic equation $x^2 + 2kx + 8k = 0$ has no real roots. [4]
\hfill \mbox{\textit{WJEC Unit 1 2022 Q9 [4]}}