Question

а) arcctg (-1)+arctg корень из 3/3 - arcctg 0 б) ctg (arccos 1/корень из 2) в)arcctg (cos пи)

Answer 1

============ a ============ 

$arcctg (-1)+arctg frac{ sqrt{3} }{3} - arcctg 0 = frac{3 pi }{4} + frac{ pi }{6} - frac{ pi }{2} = frac{9 pi +2 pi -6 pi }{12} = frac{5 pi }{12}$

============ б ============ 

$ctg (arccos frac{1}{ sqrt{2} } ) = ctg frac{ pi }{4} =1$

============ c ============ 

$arcctg (cos pi )=arcctg (-1)= frac{3 pi }{4}$