Question

Coterminal Angles!

need help asap

Answer 1

Anyone can help?, seriously stuck

Answer 2

So you need to add or subtract full laps (2pi or 360 degrees) until you get inside the interval?

Answer 3

Im not sure sometimes I see they add +4pi

Answer 4

+4pi is adding 2 laps

Answer 5

Ok I really dont know anything its our first weeks homework. So I need a full rough down on what to do

Answer 6

You will get a coterminal angle every 360 degrees, right?

Answer 7

What is a coterminal?

Answer 8

I know nothing about trig, I did precalc and did fine but this stuff is completely new to me

Answer 9

If you read the first sentences and see the first pic in this link, do you get what a coterminal angle is?
http://hotmath.com/hotmath_help/topics/coterminal-angles.html

Answer 10

Yeah, but the problems is im not given any graph

Answer 11

Right, but you won't need that :D

Answer 12

"To find a positive and a negative angle coterminal with a given angle, you can add and subtract 360° if the angle is measured in degrees or 2π if the angle is measured in radians."

Answer 13

Uh

Answer 14

for a) you have the angle -17pi/12. Add 2pi to that and you'll get a coterminal angle, which coincidentally is within the interval!

Answer 15

for b) you have the angle 810 degrees, keep subtracting 360 until you get within the interval 0 to 360 degrees.

Answer 16

Makes sense?

Answer 17

Alright im sorry im very lost

Answer 18

For a) how do I know if I need to add 2pi or -2pi or 4pi etc

Answer 19

Right so adding 4pi is the same thing as adding 2pi two times, so what you are actually doing is just add 2 laps at once

Answer 20

You know that 1 lap = 360 degrees = 2pi

Answer 21

For a) you can see that if you subtract 2pi, you will get an even bigger negative number, so you're going the wrong way, because the interval asks for 0 to 2pi

Answer 22

Im so lost is there a way for you to draw step by step what to do?

Answer 23

and I got other problem variations for the same topic

Answer 24

For a) You just add 2pi to get inside the interval:
-17*pi/12 + 2*pi =
-17*pi/12 + 24*pi/12 =
7*pi/12 <-- IS inside 0 to 2 pi interval

b) You just subtract 360 degrees to get inside the interval:
810 - 360 = 450 <-- not inside 0 to 360 degrees interval
450 - 360 = 90 degrees <-- IS inside 0 to 360 degrees interval

Answer 25

Ok for the first step you multiply by 2 add the pi symbol and make it /12 because of first fraction right?

Answer 26

and when you subtract 24-17 it gives 7pi/12

Answer 27

Right?

Answer 28

Yep, that's pretty much what I did, except in the first step; what I do is add 2*pi (a full lap)

Answer 29

Ok let me try another question

Answer 30

and see if I got it

Answer 31

Yes yes

Answer 32

Ok this time

Answer 33

It is

Answer 34

Find an angle between 0 and 2pi that is coterminal with -5pi/2

Answer 35

Right, so how'd you do this?

Answer 36

I keep losing connection

Answer 37

I keep getting kicked off with uh-oh, lost the connection.... Trying to reconnect now.

Answer 38

I got 7pi/12 is that right?

Answer 39

You sure that's what you get?
-5pi/12 + 24pi/12 = 17pi/24