Respuesta :

Answer:

x = 0°, 360°

Step-by-step explanation:

  • Formula :  cos²x + sin²x = 1
  • so sin²x = 1 - cos²x

using the formula:

cosx - 1 = 1 - cos²x

cos²x +cosx - 1 - 1 = 0

cos²x +cosx - 2 = 0

cos²x + 2cosx - cosx -2 = 0

cosx ( cosx + 2 ) -1 ( cosx + 2 ) = 0

(cosx - 1) (cosx + 2 ) = 0

cosx = 1 , cosx = -2

[tex]x = cos^{-1} ( 1 )[/tex] , [tex]x = cos^{-1} ( -2 )[/tex]

x = 0° , 360° , Not applicable

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