Problem C. 849. (March 2006)
C. 849. Evaluate cot x, given that cot x=sin x?
(5 pont)
Deadline expired on April 18, 2006.
Sorry, the solution is available only in Hungarian. Google translation
Megoldás:
cos x=sin2x,
cos2x=1-sin2x=1-cos x,
cos2x+cos x-1=0,
amiből csak a nagyobbik gyök jó. Innen , ennyi ctg x értéke is.
Statistics:
270 students sent a solution. 5 points: 96 students. 4 points: 97 students. 3 points: 50 students. 2 points: 11 students. 1 point: 6 students. 0 point: 6 students. Unfair, not evaluated: 4 solutionss.
Problems in Mathematics of KöMaL, March 2006