9709 P35 - Jun 2025 - Q6 - 9 marks
9539
The parametric equations are \(x=\dfrac2{\cos3t}\), \(y=\tan3t\), for \(0\le t\le2\pi\).
(a) Show that \(dy/dx\) can be written as \(A\operatorname{cosec}3t\), finding the constant \(A\). [5]
(b) Find the normal at \(t=\pi/12\) in the form \(y=mx+c\), with exact constants. [4]
