\( \frac{sin^2(π)}{cos^2(π)} \)+sin^2(π)-1
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sin^2(π)=1-cos^2(π)
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\( \frac{1-cos^2(π)}{cos^2(π)} \)+1-cos^2(π)-1=
=\( \frac{1-cos^2(π)}{cos^2(π)} \)-cos^2(π)=
=\( \frac{1}{cos^2(π)} \)-1-cos^2(π)=
=\( \frac{1-cos^2(π)-cos^4(π)}{cos^2(π)} \)