can you please check this problem and my solution

[ladyazpy]

evaluate the following without using the calculator?

1. cos (5 pie/3)
* cos 5*180 = 900, 900/3= 300
* 300-360= 60
the 30-60-90 angles
ans. 1/2

2. tan (5 pie/4)
1/1= 1

now my im confuse on how to scketch this remaining problem it looks easy but i can't guess which of the two special triangles i have to use

3. sin 270

4. sec 360

please could you show me the work

thank you

 

[Gene]

1. Your answer is correct but the way you showed your work is terrible!!
cos (5 pie/3)
* cos 5*180 = 900, 900/3= 300
* 300-360= 60
the 30-60-90 angles
ans. 1/2

Pie you eat. Pi is the number.
Where did the * come from? And what does it mean?
pi/3 radians = 60° not 180°
cos(5*180) is not = 900
300-360 is -60, not 60

2. "check this problem" but you don't show any work. Your answer is correct.

Think about the unit circle.
3. 270° is a line straight down to (x,y) = (0,-1)
Sin=y/1 = -1

4. 360° is a line straight right to (x,y) = (1,0)
sec(x) = 1/cos(x)
cos=x/1
sec = 1/(x/1) = 1/x = 1