This is what I did
First I took to other side resulting in
Then I divided by resulting in then I divided by 2
I am sure it's incorrect.. Can someone please help me
You can't divide by as it can be equal to 0.
Here is how to do.
factorise by cos(theta) :
the product ab=0 if and only if a=0 or b=0
----> or
For the first one... there are infinitely many solutions !
we know that
but since cos(-x)=cos(x), we know that
moreover, cos is a 2pi-periodic function.
Hence
these give all the possible solutions for cos(theta)=0
(in general, if a is such that cos(a)=b, then the solutions to cos(x)=b are in the form a+2kpi or -a+2kpi, for any integer k)
For the second one, there are infinitely many solutions too.
we know that
but we know that . Thus
again, sin is a 2pi-periodic function.
Hence
this can be rewritten :
Finally, the solutions are :
does it look good to you ?
Edit : woops, a bit late