where A+B+C = 180 degree.
Q2. P.S.:(3.14= pi )
If tanO = -(8/15) and O lies between [3(3.14)]/2 and 2(3.14) , without using calculators, find the value of {2sin( 3.14 + O)-sin[(3.14/2) - O]}/{sec(2(3.14) - O)+2tan(3.14+O)}.
please give the significant steps .
更新1:
a-maths , is there a mistake? http://hk.knowledge.yahoo.com/question/question?qid=7008121302267
更新2:
「 (sin^2x)^2 + 2sin^2xcos^2x + (cos^2x)^2 = sin^2x + 2sin^2xcos^2x (sin^2x + cos^2x)^2 = sin^2x + 2(sin^2xcos^2x)^2 」 I don't know why it is correct..please tell me by sending email to me, thanks!!
