Target Mathematics

3.54: Definite integral and reciprocal trig identity

0606/12/M/J/25 — Question 4 · 5 marks

(a)
Find 0πsinθdθ\displaystyle\int_{0}^{\pi} \mathrm{sin}\,\theta\,\mathrm{d}\theta.
[2]
(b)
Given that 0<α<π20 < \alpha < \dfrac{\pi}{2}, show that secαcotα+tanα\dfrac{\mathrm{sec}\,\alpha}{\mathrm{cot}\,\alpha + \mathrm{tan}\,\alpha} can be written as sinα\mathrm{sin}\,\alpha.
[3]