Solution 1.1:2b
From Förberedande kurs i matematik 2
The expression is a sum of two terms which we differentiate one by one,
| \displaystyle \begin{align}
f^{\,\prime}(x) &= \frac{d}{dx}\,\bigl(\cos x-\sin x\bigr)\\[5pt] &= \frac{d}{dx}\,\cos x - \frac{d}{dx}\,\sin x\\[5pt] &= -\sin x-\cos x\,\textrm{.} \end{align} |
