Solve the following equations given that $\displaystyle 0 \leq x \leq 2\pi$.
$\displaystyle a) \cos^2x - \sin^2x = 1$
$\displaystyle b) 1 + \sqrt{3}\tan2x = 0$
Your help is really appreciated. Thanks.
b) tan2X = -1/root3
Then set the range according to 2X. that is From 0<2X<4pi
then replace 2X by another variable say Y
tan Y= -1/root3
solve for Y in the new given range.
At the end divide the answers by 2, because 2X=Y. Is that Ok.