tożsamość

[Kiron2]

sprawdzic tozsamosc
\(\displaystyle{ \frac{1-2cos^{2}\alpha}{sin\alpha cos\alpha}=tg\alpha-ctg\alpha}\)

dzieki za pomoc

[bakos3321]

\(\displaystyle{ \frac{sin^2\alpha+cos^2\alpha-2cos^2\alpha}{sin\alphacos\alpha}=\frac{sin^2\alpha-cos^2\alpha}{sin\alpha cos\alpha}=\frac{sin^2\alpha}{sin\alpha cos\alpha}-\frac{cos^2\alpha}{sin\alpha cos\alpha}=\frac{sin\alpha}{cos\alpha}-\frac{cos\alpha}{sin\alpha}=tg\alpha-ctg\alpha}\)

[Kiron2]

a to?

\(\displaystyle{ tg^{2}(\frac{\Pi}{4}-\alpha)= \frac{1-sin2 }{1+sin2 }}\)

dzieki ziom za to wyzej

[bakos3321]

\(\displaystyle{ P=\frac{sin^{2}\alpha+cos^{2}\alpha-2sin\alpha cos\alpha}{sin^{2}\alpha+cos^{2}\alpha+2sin\alpha cos\alpha}=\frac{(sin\alpha-cos\alpha)^{2}}{(sin\alpha+cos\alpha)^{2}}}\)
\(\displaystyle{ L=\frac{(1-tg\alpha)^{2}}{(1+tg\alpha)^{2}}=\frac{(cos\alpha-sin\alpha)^{2}}{(cos\alpha+sin\alpha)^{2}}}\)
\(\displaystyle{ L=P}\)