What is the value of (Quant Trigo #02)

What is the value of

  1. √2
  2. 2√2
  3. √2 tan x
  4. 0

Answer

1/(1 + cos x) + 1/(1 - cos x) = (1 - cos x + 1 - cos x)/((1 + cos x)((1 - cos x)))

= 2/(1 - cos2 x)

= 2/(sin2 x)

Therefore, (sin x)√[2/(sin2 x)] = √2

The correct option is A.