math ????

[Denro]

---

Members do not see this ad.

which of the following is equal to the value of sin 5 pi/6 ???

a.) sin 11 pi/6

b.) cos pi/6

c.)sin 2pi/3

d.) cos 2pi/ 3

e.) cos 5pi/3

sorry i couldnt find the pie symbol so i just wrote it in.. but my question is ..whats the best way to figure this problem beside memorizing all the radians and degrees.. is there a method u can use? and by the way the answer is E

 

[amino]

You know that they are asking for sin 30 degrees (2nd quadrant) where sin is positive 👍. sinx=cos(90-x) so, looking for a positive value for cos 60 which is 5pi/3------in the 4th quadrant, where cos is positive (x). Its probably easiest to plug and play with these type of problems. Find the reference angle and go from there.

note: sin 30 and cos 60 are reference angles----the angles are 150 and 300 respectively....


keep practicing and doing problem after problem until this kind of stuff sinks in. It may take a while, but you will get the hang of it.

a