4 sec^2 x + 2 tan^2 x − 6 = 0
Did you give it a go already?
\(4 sec^2 x + 2 tan^2 x − 6 = 0\\~\\ hint:\\ sin^2x+cos^2x=1\\ \text { if i divide by }cos^2x \text{ then I get}\\ tan^2x+1=sec^2x \)
Now I did one of these for you just a moment ato so you should be able to finish it.
