Kako pretvorite (11, -9) v polarne koordinate?

Kako pretvorite (11, -9) v polarne koordinate?
Anonim

Odgovor:

# (sqrt202, tan ^ -1 (-9/11) + 2pi) ali (14,2,5,60 ^ c) #

Pojasnilo:

# (x, y) -> (r, theta); (r, theta) = (sqrt (x ^ 2 + y ^ 2), tan ^ -1 (y / x)) #

# r = sqrt (x ^ 2 + y ^ 2) = sqrt (11 ^ 2 + (- 9) ^ 2) = sqrt (121 + 81) = sqrt202 ~~ 14.2 #

# theta = tan ^ -1 (-9/11) #

Vendar pa #(11,-9)# je v kvadrantu 4, zato moramo dodati # 2pi # na naš odgovor.

# theta = tan ^ -1 (-9 / 11) + 2pi ~~ 5.60 ^ c #

# (sqrt202, tan ^ -1 (-9/11) + 2pi) ali (14,2,5,60 ^ c) #