BITSAT2019MathematicsFunctionsActual
Number of solution of the equation | cos x | = 2 [ x ] are (where | x | , [ x ] are modulus and greatest integer function respectively).
Options
- A0
- B2
- C1
- Dinfinitely many
Correct answer
A. 0
Step-by-step solution
Given, | cos x | = 2 [ x ] 0 ≤ | cos x | ≤ 1 ∴   0 ≤ 2 [ x ] ≤ 1 0 ≤ [ x ] ≤ 1 2 x = 0 ⇒ x ∈ [ 0 , 1 ) But | cos x | = 0 ⇒ x = n π + π 2 for any value of n ∈ Z Hence, the equation has no solution.