tg(?+?)=(tg?+tg?)/(1tg?·tg?); tg(?-?)=(tg?tg?)/(1+tg?·tg?)
ctg(?+?)=(ctg?·ctg?1)/(ctg?+ctg?); ctg(?+?)=(ctg?·ctg?+1)/(ctg?ctg?)
sin?+sin?=2sin½(?+?)cos½(?-?); sin?-sin?=2cos½(?+?)sin ½(?-?)
cos?+cos?=2cos½(?+?)cos½(?-?); cos?-cos?=-2sin½(?+?)sin ½(?-?)
a·sinx+b·cosx=?(a²+b²)sin(x+?), tg?=b/a
tg? ? tg?=sin(?+?)/(cos?·cos?); ctg? ? ctg?=sin(???)/(sin?·sin?)
sin²?sin²?=cos²?cos²?=sin(?+?)sin(?-?)
cos²?sin²?=cos²?sin²?=cos(?+?)cos(?-?)
sin?·sin?=½[cos(?-?)cos(?+?)]; cos?·cos?=½[cos(?-?)+cos(?+?)]
sin?·cos?=½[sin(?+?)+sin(?-?)]
tg?·tg?=(tg?+tg?)/(ctg?+ctg?)=-(tg?tg?)/(ctg?ctg?)
ctg?·tg?=(ctg?+tg?)/(tg?+ctg?)=-(ctg?tg?)/(tg?ctg?)
ctg?·ctg?=(ctg?+ctg?)/(tg?+tg?)=-(ctg?ctg?)/(tg?tg?)
sin½?=??((1cos?)/2); sin?=(2tg½?)/(1+tg² ½?)
sin2?=2 sin?·cos?; sin3?=3sin?4sin³?
sin²?=½(1cos2?); sin³?=(3 sin? sin 3?) / 4
cos½?=??[(1+cos?)/2]; cos?=(1tg² ½?)/(1+tg² ½?)
cos2?=cos²?sin²?=12 sin²?=2cos²?1; cos3?=4cos³?3 cos?
cos²?=½(1+cos2?);cos³?=(3cos?+cos3?)/4
tg½?=sin?/(1+cos?)=(1cos?)/sin?= ??((1cos?)/(1+cos?))
tg?=(2tg½?)/(1tg² ½?); tg2?=(2tg?)/(1tg²?)=2/(ctg?tg?)
tg3?=(3tg?tg³?)/(13tg²?)=tg?·tg(?/3+?)·tg(?/3?)
ctg½?=sin?/(1cos?)=(1+cos?)/sin?=??((1+cos?)/(1cos?))
ctg?=(ctg² ½?1)/2ctg ½?; ctg2?=(ctg²?1)/2ctg?=½(ctg?tg?)
ctg3?=(3ctg?ctg³?)/(13 ctg²?)
tg(¼+?)=(sin?+cos?)/(sin?cos?); tg(¼?)=(sin?cos?)/(sin?+cos?)