Question

Pomocy!!! Oblicz.
sin172*
cos130*
ctg405*
sin(-1395*)
tg(-660*)

Answer 1

Sin 172* = sin(180*-8*) = sin 8* ≈ 0,1392 ( z tablic)
cos 130* = cos (90*+ 40*) = -sin 40* ≈ -0,6428
ctg 405* = ctg (360*+ 45*) = ctg 45* = 1
sin(-1395*) = -sin 1395* = -sin(3*360* + 315) = -sin 315* = -sin(270*+45*) = -(-cos 45*)  = √2/2
tg(-660*) = -tg660* =-tg(360* + 300*) = -tg 300* = -tg (270* + 30*) = -(-ctg 30*) = √3
 Wszystkie obliczenia w oparciu o wzory redukcyjne.