## Thomas' Calculus 13th Edition

$p^{\prime}=sec^2q$
As given that $p=5+\frac{1}{cotq}$ $p=5+tanq$ (because tan $\theta$ and $cot \theta$ are reciprocals) We differentiate both sides to obtain: $p^{\prime}=0+sec^2q$ $p^{\prime}=sec^2q$