Question

Solve cos (3 theta)= 1

Answer 1

\(cos3\theta=1~ means ~3\theta=2k\pi ~or~ 3\theta=\pi+2k\pi~ ~; k=0,\pm1, \pm2,\pm3..... \)

Answer 2

solve for theta

Answer 3

Would it be theta= cos^-1(1)

Answer 4

nope that won't quite work
and by the way it is 3theta=cos^-1(1)
Not theta

Answer 5

So what do I due then?

Answer 6

oh by the way i made a mistake is should be 3theta=2kpi

the other part is wrong! i was thinking something else

Answer 7

you just solve for theta here
\(3\theta=2k\pi\)

Answer 8

What does k stand for?

Answer 9

that's all you can do
if you specify an interval we could give some exact values for theta

Answer 10

i wrote it about k is any integer

Answer 11

above*

Answer 12

I put it in the cal. And got 0

Answer 13

you can't put it calc
your answer is \(\large\theta=\frac{2k\pi}{3}\)
that's all you can do
unless you specify what interval you want like [0, 2pi]

Answer 14

The intervals are 0 equal or greater than theta equal or greater than 2pi

Answer 15

you see you said just solve, you have to include every detail of the problem
without missing any piece so we know where are headed!
if you just say solve this! that's mean you are looking for a general solution!
now between 0 an 2pi there are only two values that make cos=1
and those are 0 and 2pi themselves
in our problem we have
3theta=0 or 3theta=2pi
meaning that theta=0 or theta=2pi/3

Answer 16

That's it!

Answer 17

what else you want that's all.
you have two possible answers for theta
0 or 2pi/3

Answer 18

Thanks

Answer 19

make sure next time to include whatever the problem states! don't miss any thing

Answer 20

you are welcome