Question

como calcular o cosseno de 25π/3?

Answer 1

tg(25π/3) = tg(24π/3 + π/3) 
tg(25π/3) = tg(8π + π/3) 
tg(25π/3) = sen(8π + π/3)/cos(8π + π/3) 

sen(8π + π/3) = sen(8π)cos(π/3) + cos(8π)sen(π/3) 
sen(8π + π/3) = 0.1/2 + 1.√3/2 
sen(8π + π/3) = √3/2 

cos(8π + π/3) = cos(8π)cos(π/3) - sen(8π)sen(π/3) 
cos(8π + π/3) = 1.1/2 - 0.√3/2 
cos(8π + π/3) = 1/2 

tg(25π/3) = sen(25π/3)/cos(25π/3) 
tg(25π/3) = (√3/2)/(1/2) 
tg(25π/3) = √3