Apologies for that, here's the cleaned up, comprehensible version of the question (thanks to Mark44):
Let ##I_n = \int_0^{\pi/2} x \cos^n(x) dx##, with ##n \ge 0##
i) Show that ##n I_n = (n - 1)I_{n-2} - n^{- 1}##, for ##n \ge 2##.
ii) Find the exact value of ##I_3##.