Question

Calculati:
a) sin 30 grade cos 60 grade + sin 60 grade cos 30 grade
b) sin 30 grade cos 30 grade cos 60 grade
c)sin 45 grade cos 30 grade - sin 30 grade cos 45 grade
d) sin² 30 grade+ cos² 30 grade
e)tg 60 grade * ctg 60 grade
f) tg 30 grade +ctg 30 grade

Answer 1

a) sin 30 grade cos 60 grade + sin 60 grade cos 30 grade=
=1/2 x 1/2 + √3/2 x√3/2 =1/4+3/4=1
b) sin 30 grade cos 30 grade cos 60 grade =
=1/2x√3/2 x1/2=√3/6 
c)sin 45 grade cos 30 grade - sin 30 grade cos 45 grade=
=√2/2x√3/2-1/2x√2/2=√6/4-√2/4=(√6-√2)/4
d) sin² 30 grade+ cos² 30 grade =
=(1/2)²+(√3/2)²=1/4+3/4=1
e)tg 60 grade * ctg 60 grade=√3x1/√3=1
f) tg 30 grade +ctg 30 grade=1/√3+√3=√3/3+√3=4√3/3