Sin theta / x = cos theta / y potem sin theta - cos theta =?

Odgovor:

Če # frac {sin theta} {x} = frac {cos theta} {y} # potem # the the - cos theta = pm frac {x - y} {sqrt {x ^ 2 + y ^ 2}} #

Pojasnilo:

# frac {sin theta} {x} = frac {cos theta} {y} #

# frac {sin theta} {cos theta} = frac {x} {y} #

# anta = x / y # t

To je kot pravokoten trikotnik z nasprotnim # x # in v bližini # y # tako

#cos theta = frac {{pm y} {sqrt {x ^ 2 + y ^ 2} #

# sin theta = anta cos theta #

# the theta - cos theta #

# = tan theta cos theta - cos theta #

# = cos theta (theta - 1) #

# = frac {; pm y} {sqrt {x ^ 2 + y ^ 2}} (x / y -1) #

# the the - cos theta = pm frac {x - y} {sqrt {x ^ 2 + y ^ 2}} #