Saturday, 21 February 2009
my solutions:
alternatively, you can expand cos4A out with double angle formula etc to cos^2 2A and use double angle again etc etc.
today's qns:
1. Given that sinx + cosx = 1/3 , find the value of
a)sinxcosx
b)tanx + cotx
2. Prove that tan^2 (45º+ α) = (1+sin2α) / (1-sin2α)
posted by xlifenotex @ 1:55 pm
