SOLUTION: I have been ill and have missed several weeks of school. I am trying to catch up now that I am home from the hospital via email. My pre-cal/trig teacher sent me several homework as

Question 836440: I have been ill and have missed several weeks of school. I am trying to catch up now that I am home from the hospital via email. My pre-cal/trig teacher sent me several homework assignments, but I am so behind that I do not now how to do these problems. Can you help with this one and maybe I can use it as an example? I am supposed o evaluate using principle values of the inverse relations.
The problem: cos(2 arc cos 5/6)
Thank you so much!!!
Answer by rothauserc(4718) (Show Source): You can put this solution on YOUR website!
begin by evaluating arccos(5/6) which is 33.557 degrees
now multiply 33.557 by 2 and evaluate the cosine
cos (2 * 33.557) = 0.39

RELATED QUESTIONS
I have been ill and have missed several weeks of school. I am trying to catch up now that (answered by josmiceli)

You have borrowed $200000 at 7% p.a taken over 25 years a)How much is the standard... (answered by xcentaur)

Martina leaves home at 9 A.M., bicycling at a rate of 24mi/h. Two hours later, John... (answered by venugopalramana)

I thank you guys for helping me so much. Up into now i have been doing pretty well now... (answered by Earlsdon)

I am homeschooled with the School of Tomorrow. I have no teacher, and am struggling with (answered by Mathtut,josmiceli)

Solve by elimination method 0.05x+0.25y=66 0.15x+0.05y=72 I have been trying to... (answered by ewatrrr)

I can not understand how to factor trinomials in ax^2+bx+c format. I have been studying... (answered by mananth)

This is on a hand-out from my teacher I am ill and being home schooled so I have missed... (answered by bucky)

f(x)=x^2+2x+15 I am a bit confused on graphing parabolas...I missed that day of... (answered by richwmiller)