Kako rešite sin (x) - cos (x) -tan (x) = -1?

Kako rešite sin (x) - cos (x) -tan (x) = -1?
Anonim

Odgovor:

# "Set rešitev" = {2kpi} uu {kpi + pi / 4}, k v ZZ #.

Pojasnilo:

Glede na to, # sinx-cosx-tanx = -1 #.

#:. sinx-cosx-sinx / cosx + 1 = 0 #.

#:. (sinx-cosx) - (sinx / cosx-1) = 0 #.

#:. (sinx-cosx) - (sinx-cosx) / cosx = 0 #.

#:. (sinx-cosx) cosx- (sinx-cosx) = 0 #.

#:. (sinx-cosx) (cosx-1) = 0 #.

#:. sinx = cosx ali cosx = 1 #.

# "Primer 1:" sinx = cosx #.

Opazujte to #cosx! = 0, ker, "če je drugače;" tanx "postane" #

nedoločeno.

Zato delimo s #cosx! = 0, sinx / cosx = 1 ali tanx = 1 #.

#:. tanx = tan (pi / 4) #.

#:. x = kpi + pi / 4, k v ZZ, "v tem primeru" #.

# "Primer 2:" cosx = 1 #.

# "V tem primeru," cosx = 1 = cos0,:. x = 2kpi + -0, k v ZZ #.

Skupaj imamo, # "Set rešitev" = {2kpi} uu {kpi + pi / 4}, k v ZZ #.

Odgovor:

# rarrx = 2npi, npi + pi / 4 # kje #n v ZZ #

Pojasnilo:

# rarrsinx-cosx-tanx = -1 #

# rarrsinx-cosx-sinx / cosx + 1 = 0 #

#rarr (sinx * cosx-cos ^ 2x-sinx + cosx) / cosx = 0 #

# rarrsinx * cosx-sinx-cos ^ 2x + cosx = 0 #

#rarrsinx (cosx-1) -cosx (cosx-1) = 0 #

#rarr (cosx-1) (sinx-cosx) = 0 #

Kdaj # rarrcosx-1 = 0 #

# rarrcosx = cos0 #

# rarrx = 2npi + -0 = 2npi # kje #n v ZZ #

Kdaj # rarrsinx-cosx = 0 #

#rarrcos (90-x) -cosx = 0 #

# rarr2sin ((90-x + x) / 2) * sin ((x-90 + x) / 2) = 0 #

#rarrsin (x-pi / 4) = 0 # Kot #sin (pi / 4)! = 0 #

# rarrx-pi / 4 = npi #

# rarrx = npi + pi / 4 # kje #n v ZZ #