3cos^2(x)-sin^2(x)=0

Write the equation in terms of sin or cos alone. Then, solve for x.

i.e. in terms of sin alone:

\(\displaystyle 3(1-sin^{2}(x))-sin^{2}(x)=0\)

Now, continue?.

It would appear there are 4 solutions in the given interval.

Graphing helps.

Remember, the period of sin or cos.
 
ceason2011 said:
show all solutions on the given interval [0, 2pi)

or you could continue from

\(\displaystyle 3cos^2(x) \ - \ [1 \ - \ cos^2(x)] \ = \ 0\)
 
Top