Here's the question you clicked on:
gies28
How many degrees are in 3pi/2 radians?
A full circle is 360 degrees. If you take the Unit circle, the circumference is 2*pi*r=2*pi*1=2pi. Because the radian is the same unit as the length of the unit circle, there are also 2pi radians in a full circle. So remember: 360 degrees = 2pi radians. Now can you see the number of degrees in 3pi/2 (= 3/2*pi) radians?
pi = 180 3pi/2 = 3(180)/2 = 3(90) = ?
You can't make it any more obvious than that.
What is the exact value of cos 45° as found on the unit circle?
I'm only going to show you this once...I hope you understand it
\[\sin(0,30,45,60,90) = \frac{\sqrt{0,1,2,3,4}}{2}\] \[\cos(0,30,45,60,90) = \frac{\sqrt{4,3,2,1,0}}{2}\]