1. 3tg45°-√3ctg60°+4sin30°=3*1-√3*√3/3+4*0.5=3-1+2=4
2. (8/√3)*cos π/6-7sinπ+√2sin π/4+2ctg 3π/4=
(8/√3)*√3/2-7*0+√2*√2/2+2*(-1)=4+1-2=3
13cos(π/2-α)=13sinα
это угол четвертой четверти, там косинус положителен. а синус отрицателен, поэтому sinα= - √(1-(144/169))= -5/13, тогда 13sinα=
13*(-5/13)=-5
4. ctg(π/2-α)=tgα=-3, это угол второй четверти. косинус там отрицателен, как и котангенс, а синус положителен.
1/cos²α=1+ tg²α
cosα=-√(1/(1+tgα))=-√(1/1+9)=-√10/10
In the first picture, the girl is listening to music and from her face, we can understand that she is enjoying it.
Then, in the second picture, the boy is drawing a picture with colored pencils.
In the third, the group of kids is doing a piece of art. The boy with brown hair is drawing a picture, while a girl with black hair is doing pottery. (По картинке я не понял что делают другие)
In the last picture, the kids are playing in the band. We can see that the first boy in a yellow T-shirt is singing a song while his friends are playing on different instruments.
In the first picture, the girl is listening to music and from her face, we can understand that she is enjoying it.
Then, in the second picture, the boy is drawing a picture with colored pencils.
In the third, the group of kids is doing a piece of art. The boy with brown hair is drawing a picture, while a girl with black hair is doing pottery. (По картинке я не понял что делают другие)
In the last picture, the kids are playing in the band. We can see that the first boy in a yellow T-shirt is singing a song while his friends are playing on different instruments.
Решение задания прилагаю