Question
If a function f : R -\ l\ R -\ m\ defined by f(x)= x+3 x-2 is a bijection, then 3 l+2 m=
BITSAT
Mathematics
Functions
2024
BITSAT 2024 (Memory Based Paper 1)
BITSAT Mathematics Question (2024) — Solution
Options
- A. 10
- B. 12
- C. 8
- D. 14
Answer
C. 8
Step-by-step solution
f(x)= x+3 x-2 f(x) is not defined for x=2 i.e. domain of f(x) is R -\ 2\ l=2 Now, y= x+3 x-2 x y-2 y=x+3 x(y-1)=2 y+3 x= 2 y+3 y-1 y can take any value except y=1 Co-domain = R -\ 1\ m=1 3 l+2 m=3(2)+2(1)=8
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