Kako poenostavite (1 - sin ^ 2 theta) / (csc ^ 2 theta -1)?

Kako poenostavite (1 - sin ^ 2 theta) / (csc ^ 2 theta -1)?
Anonim

Odgovor:

# sin ^ 2theta #

Razen ko #theta = pi / 2 + npi, n v ZZ # (Glej Zorjevo pojasnilo)

Pojasnilo:

Najprej moramo posebej pogledati števec in imenovalec.

# 1-sin ^ 2theta = cos ^ 2theta #

# csc ^ 2theta = 1 / (sin ^ 2theta) #

# 1 / (sin ^ 2theta) - 1 = (1-sin ^ 2theta) / (sin ^ 2theta) = (cos ^ 2theta) / (sin ^ 2theta) #

Torej

# (1-sin ^ 2theta) / (csc ^ 2theta-1) = (cos ^ 2theta) / ((cos ^ 2theta) / (sin ^ 2theta)) = sin ^ 2theta #