wyznacz tg

[maxiking99]

\(\displaystyle{ sin ^{4} \alpha +cos ^{4} \alpha = \frac{5}{9}}\)
oblicz \(\displaystyle{ tg ^{2} \alpha}\)

[Dasio11]

Hint:    

\(\displaystyle{ (\sin^2 \alpha + \cos^2 \alpha)^2=1}\)