Qual è il valore di #cos (7pi / 4) #?
Looking at the angle:
#7pi/4# equivale a #-pi/4# e #cos# is an even function so:
#cos(-x)=cos(x)#
Così:
#cos(7pi/4)=cos(-pi/4)=cos(pi/4)=sqrt(2)/2#
Looking at the angle:
#7pi/4# equivale a #-pi/4# e #cos# is an even function so:
#cos(-x)=cos(x)#
Così:
#cos(7pi/4)=cos(-pi/4)=cos(pi/4)=sqrt(2)/2#