NTA Abhyas JEE Main2020MathematicsFunctionsPractice
If f : A → B defined by f x = s i n x - c o s x + 3 2 is an invertible function, then the correct statement can be
Options
- AA = π 4 , 5 π 4 , B = 3 2 , 4 2
- BA = - π 4 , 5 π 4 , B = 2 2 , 4 2
- CA = - π 4 , 3 π 4 , B = 2 , 4 2
- DA = - π 4 , 3 π 4 , B = 2 2 , 4 2
Correct answer
D. A = - π 4 , 3 π 4 , B = 2 2 , 4 2
Step-by-step solution
f x = 2 1 2 sin ⁡ x - 1 2 cos ⁡ x + 3 2 = 2 s i n x - π 4 + 3 2 Clearly, for options A and B f x is not injective and for the option C f x is not surjective Hence, f x is bijective only for option D