JEE Previous Year Question
Let S = The sum of all distinct solutions of the equation
sec x + cosec x + 2(tan x – cot x) = 0 in the set S is equal to
Topic: JEE PYQ
Answer: C. Full step-by-step solution below.
- A–
- B–
- C0
- D
Correct answer: C
Solution
(c)secx + cosecx + 2 (tanx – cotx) = 0⇒ sinx + cosx + 2 (sin2x – cos2x ) = 0
sinx + cosx – 2cos2x = 0 ⇒ sin = cos2x
cos (π/3 – x) = cos2x ⇒ 2x = 2nπ ± (π/3 – x)
x = or x = 2nπ –.
– – 60 o + 20 o +140 o = 0