| Exam Board | OCR MEI |
|---|---|
| Module | C1 (Core Mathematics 1) |
| Marks | 3 |
| Paper | Download PDF ↗ |
| Mark scheme | Download PDF ↗ |
| Topic | Trig Proofs |
| Type | Logical implication symbols (⇒, ⇔, ⇐) |
| Difficulty | Easy -1.8 This is a basic logic question testing understanding of implication symbols through simple examples requiring minimal mathematical reasoning. The quadrilateral example uses elementary geometry definitions, while the number theory examples involve straightforward parity checks—all well below typical A-level problem-solving demands. |
| Spec | 1.01b Logical connectives: congruence, if-then, if and only if |
| Answer | Marks | Guidance |
|---|---|---|
| Answer | Marks | Guidance |
| (i) \(\Leftarrow Q\) | 1 | or \(\Leftarrow\) or '\(Q \Rightarrow P\)'. Condone single arrows |
| (ii) none [of the above] | 1 | |
| (iii) \(\Rightarrow Q\) | 1 | or \(\Rightarrow\) |
## Question 3:
| Answer | Marks | Guidance |
|--------|-------|----------|
| (i) $\Leftarrow Q$ | 1 | or $\Leftarrow$ or '$Q \Rightarrow P$'. Condone single arrows |
| (ii) none [of the above] | 1 | |
| (iii) $\Rightarrow Q$ | 1 | or $\Rightarrow$ |
---3 Select the best statement from
$$\begin{aligned}
& \mathrm { P } \Rightarrow \mathrm { Q } \\
& \mathrm { P } \Leftarrow \mathrm { Q } \\
& \mathrm { P } \Leftrightarrow \mathrm { Q }
\end{aligned}$$
none of the above\\
to describe the relationship between P and Q in each of the following cases.\\
(i) P: WXYZ is a quadrilateral with 4 equal sides\\
$\mathrm { Q } : \mathrm { WXYZ }$ is a square\\
(ii) P: $n$ is an odd integer
Q : $\quad ( n + 1 ) ^ { 2 }$ is an odd integer\\
(iii) P : $n$ is greater than 1 and $n$ is a prime number
Q : $\sqrt { n }$ is not an integer
\hfill \mbox{\textit{OCR MEI C1 Q3 [3]}}