Find $\frac{dy}{dx}$ if $x - y = \pi$.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 1 ##
Differentiating the relationship w.r.t., $x$, we have
$\frac{d}{dx}(x - y) = \frac{d\pi}{dx}$
Recall that $\frac{d\pi}{dx}$ means to differentiate the constant function taking value $\pi$ everywhere w.r.t., $x$. Thus
$\frac{d}{dx}(x) - \frac{d}{dx}(y) = 0$
which implies that
$\frac{dy}{dx} = \frac{dx}{dx} = 1$