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Question: Answered & Verified by Expert
If fx=1|x|;|x|1ax2+b;|x|<1 is differentiable at every point of the domain, then the values of a and b are respectively:
MathematicsContinuity and DifferentiabilityJEE MainJEE Main 2021 (18 Mar Shift 1)
Options:
  • A 12,12
  • B 12,-32
  • C 52,-32
  • D -12,32
Solution:
2603 Upvotes Verified Answer
The correct answer is: -12,32

fx=1|x|,|x|1ax2+b,|x|<1

at x=1 function must be continuous

So, 1=a+b 1

differentiability at x=1

-1x2x=1=(2·ax)x=1

-1=2aa=-12

Put in (1)b=1+12=32

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