Question

Решите, ответ округлите до десятых
cos(arccos0,9)+arccos(cos4π/4)+arccos(−√3/2)

Answer 1

$cos(arccos(0,9))+arccos(cos( frac{4pi}{4} ))+arccos(-frac{ sqrt{3} }{2} )\cos(arccos(x))=x\0,9+arccos(cos(pi)+frac{5pi}{6} =0,9+pi+frac{5pi}{6} =\=frac{9}{10} +frac{11pi}{6} \frac{11*3,14}{6} =frac{frac{1727}{50} }{6} =5frac{227}{300} =5,75\0,9+5,75=6,65$