Question

Determine o valor de A=sen 105°+cos105°

Answer 1

a=sen 105°+cos 105°
a² =(sen 105°+ cos 105°)²
a²=sen² 105° + cos² 105+2sen 105°cos 105°
a² =1+sen 210°
a²=1-sen 30°
a² =1-1/2=1/2
a=√2/2