Question

Ada yang tau cara no 6 yang A, digambar ini ?

Answer 1

6a. (tan x+sec x)(tan x-sec x)
      = tan² x - sec² x
      = (sin² x - 1)/cos² x
      = -cos² x/cos² x
      = -1

6b. 1/(1+cos x) + 1/(1-cos x)
      = (1-cosx + 1+cosx)/(1-cos² x)
      = 2/sin² x

6c. tan x - (sec² x/tan x)
      = (tan² x - sec² x)/tan x
      = (-cos² x/cos² x)/tan x
      = -1/tan x
      = -cotg x

6d. cos x/(1+sin x) + (1+sin x)/cos x
      = (cos² x + (1+sin x)²)/(1+sin x).cos x
      = (cos² x+sin² x+2.sin x+1)/(1+sin x).cos x
      = (2+2sin x)/(1+sin x).cos x
      = 2.(1+sin x)/(1+sin x).cos x
      = 2/cos x