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Question: Answered & Verified by Expert
Let f:RR be defined as fx=2 x-1 and g:R-1R. be defined as gx=x-12x-1. Then the composition function fgx is:
MathematicsFunctionsJEE MainJEE Main 2021 (24 Feb Shift 1)
Options:
  • A neither one-one nor onto
  • B one-one but not onto
  • C onto but not one-one
  • D both one-one and onto
Solution:
2718 Upvotes Verified Answer
The correct answer is: one-one but not onto
fgx=2gx-1=22x-12x-1-1.

=xx-1=1+1x-1

Range of fgx=R-1

Range of fgx is not onto

fgx is one-one

So fgx is one-one but not onto.

one-one, into

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