Come valuta #cos (pi / 8) #?
Come valuta #cos (pi / 8) #? Risposta: #cos(pi/8) = sqrt(1/2+sqrt(2)/4)# Spiegazione: #”Use the double-angle formula for cos(x) : “# #cos(2x) = 2 cos^2(x) – 1# #=> cos(x) = pm sqrt((1 + cos(2x))/2)# #”Now fill in x = “pi/8# #=> cos(pi/8) = pm sqrt((1 + cos(pi/4))/2)# #=> cos(pi/8) = sqrt((1+sqrt(2)/2)/2)# #=> cos(pi/8) = sqrt(1/2+sqrt(2)/4)# #”Remarks … Leggi tutto