-- Posted by what the mong at 9:11 pm on Dec. 3, 2008 cos(arccot 8) and sin[arcsin 2/3]        ------            2 thats 2 thirds divided by two points will be given out for an exact answer with work explained! hundreds of points up for grabs -- Posted by XOallixs0n at 9:12 pm on Dec. 3, 2008 Aaaah. Trig <3 -- Posted by xxbarbiexx at 9:12 pm on Dec. 3, 2008 ??? uh no -- Posted by ang42490424 at 9:12 pm on Dec. 3, 2008 I don't remember how to do that. I have forgotten that part of math class. -- Posted by Love Today at 9:19 pm on Dec. 3, 2008 I don't want to take the chance of failing you @ life. -- Posted by Lukerules12 at 2:51 am on Dec. 5, 2008 1? -- Posted by Just Waiting Here at 1:20 pm on Dec. 17, 2008 Do you have the answers? cos(arccos 8) = 8 You wrote arccot... was that a typo, or is that actually what you need to solve?  I solved for arc cos. sin[arcsin 2/3]  = 1/3       ------           2 Do you know what the relationship between sin and arc sin is... or the relationship between cos and arc cos? Basically... they are inverse's of one another.  So... if... cos x = y  then... arccos y = x This being said, when you take the cos or arccos, it's just the number that you have there.  Let's take the general case. Let... cos y = x... then, by definition arccos x = y so... what is cos(arccos x)? Well... arccos x = y.  So we plug that in, and we get... cos(arccos x) = cos (y).  From above, we stated that cos y = x. Therefore... cos y = x. Using that in your first problem... the answer would just be 8 (if it was arc cos) Similar steps are taken for the second problem.  So it would just be (2/3)/2