Thread: incredibly important and due tomorrow homework

How do I find the value of x in tan(2x)-4tan(x)=3 ?

You could use the substitution $\displaystyle tan(2x)=\frac{2tan(x)}{1-tan^{2}(x)}$

After you do that, simplify and make the substitution u=tan(x).

You should get the cubic. $\displaystyle 4u^{3}+3u^{2}-2u-3=0$

Solve for u, then find x by taking arctan(u).

thank you