**TI82** TxtView file generated by CalcText - Kouri˝ ®cossin®¬˙formule trigocos(a+b)=cosacosb-sinasinb cos(a-b)=cosacosb+sinasinb sin(a+b)cosbsina+cosasinb sin(a-b)=cosbsina-cosasinb cos˛x+sin˛x=1 cos2x=cos˛x-sin˛x cos2x=2cos˛x-1 cos2x=1-2sin˛x sin2x=2sinxcosx cos(x+pi)= -cosx sin(x+pi)= -sinx cos(pi-x)=-cosx sin(pi-x)=sinx cos(pi/2 +x)= -sinx sin(pi/2 +x)= cosx cos(pi/2 -x)= sinx sin(pi/2 -x)= cosx cos(-x)= cosx sin(-x)= -sinx cos'x= -sinx sin'x= cosx˙SŤ