| Exam Board | Edexcel |
|---|---|
| Module | C3 (Core Mathematics 3) |
| Marks | 4 |
| Paper | Download PDF ↗ |
| Topic | Reciprocal Trig & Identities |
| Type | Differentiation of reciprocal functions |
| Difficulty | Moderate -0.5 This is a straightforward application of the quotient rule to tan x = sin x / cos x, requiring only standard differentiation techniques and basic trig identities. It's slightly easier than average because it's a guided proof with a known result, requiring no problem-solving insight—just mechanical application of rules. |
| Spec | 1.07h Differentiation from first principles: for sin(x) and cos(x)1.07r Chain rule: dy/dx = dy/du * du/dx and connected rates |
Use the derivatives of $\sin x$ and $\cos x$ to prove that the derivative of $\tan x$ is $\sec^2 x$. [4]
\hfill \mbox{\textit{Edexcel C3 Q11 [4]}}