Question

4. Hitunglah hasilnya 3. tan π + 4. cos π - sin π

Fast respon ya!!! senin dikumpulkan jangan lupa disertai metode / cara pengerjaannya!!

Answer 1

Sebaiknya udah  ke derajat
π rad   = 180°
tan 5/6 π= tan ( 5/6x 180) = tan 150= tan (180-30) = - tan 30= - 1/√3

cos 11/12 π = cos (11/12x 180) = cos 165 = cos (180-15) = - cos 15
- cos 15 =  - { cos (45-30)} = - ( cos 45 cos 30 + sin 45 sin 30)
= - ( 1/2√ 2 . 1/2√3 + 1/2√2 . 1/2)
= - (1/4√6 + 1/4 √2)
= -1/4 √6 - 1/4 √2

sin 2/3π = sin (2/3 x 180) = sin 120 = sin(180-60) = sin 60 = 1/2 √3

3 tan 5/6 π + 4. cos 11/12 π - sin 2/3 π =
= 3(- 1/3 √3) + 4 (-1/4 √6 - 1/4 √2) - 1/2 √3
= -√3 - √6 - √2 - 1/2 √3
= - 3/2 √3 - √6 - √2