Oblcz wartosc

[marcin2447]

Wiedząc,że \(\displaystyle{ sin(180^0+\alpha )=- \frac{1}{2}}\) i \(\displaystyle{ 0^0<\alpha <90^0}\), Oblicz
\(\displaystyle{ a) \frac{tg(180^0-\alpha)+cos(270^0-\alpha ) }{cos(90^0+\alpha) }}\)
\(\displaystyle{ b) \frac{1}{tg(180^0+\alpha )} + \frac{sin(180^0-\alpha )}{cos(180^0+\alpha )}}\)

Wiedząc że \(\displaystyle{ tg\alpha + \frac{1}{tg\alpha }=2}\), oblicz wartosc wyrażenia \(\displaystyle{ \sqrt{tg^2\alpha + \frac{1}{tg^2\alpha } }}\)

[anna_]

najpierw policz
\(\displaystyle{ tg\alpha + \frac{1}{tg\alpha }=2 \ /()^2}\)
powinno wyjść
\(\displaystyle{ tg^2\alpha + \frac{1}{tg^2\alpha }=2}\)
a potem
\(\displaystyle{ \sqrt{tg^2\alpha + \frac{1}{tg^2\alpha } }}\)