Question

Вычислите 4sin² 120°-2cos600°+√27tg660°

Answer 1

4sin² 120°-2cos600°+√27tg660°=4sin² (180-60)-2cos(360+240) +3√3tg(360+300)= 4sin² 60-2cos240 +3√3tg300= 4(√3/2)²-2cos(180+60) +3√3tg(180+120)= 4*3/4 +2cos60 +3√3tg120= 3 +2*1/2 +3√3tg(180-60) = 3 +1 -3√3tg60 =4-3√3*√3=4-9=-5