3) Daca x€ (0, π/2) si cos x= 8/17, sa se calculeze:
a)sinx
b)tgx
c)ctgx
d)sin2x
e)cos2x
f)tg2x
4)Sa se calculeze:
a)cos 450°
b)sin (33 π)/4
Am nevoie urgent dau coroana
