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Two mappings f:R to R and g:R to R are d...

Two mappings `f:R to R` and `g:R to R` are defined as follows:
`f(x)={(0,"when x is rational"),(1,"when x is irrational"):}` and
`g(x)={(-1,"wnen x is rational"),(0,"when x is irrational"):}` then the value of `[(gof)(e)+(fog)(pi)]` is -

A

0

B

-1

C

1

D

2

Text Solution

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The correct Answer is:
B
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Knowledge Check

  • A function is defined as, f(x)={(0, where x is rational),(1, where x is irrational)}: . Then f(x) is

    A
    continuous for all `x in R`
    B
    continuous for all `x in R-{0}`
    C
    continuous for all `x in R-{0,1}`
    D
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  • Let f:RrarrR be defined as . f(x)={(0, "x is irrational"),(sin|x|,"x is irrational"):} Then which of the following is true?

    A
    f is discontinuous for all x
    B
    f is continuous for all x
    C
    f is discontinuous at `x=kpi`, where kis an integer
    D
    f is continuous at `x=kpi`, where kis an integer
  • Let f(x)={(-1+sinK_1pix, x is rational), (1+cosK_2pix, x is irrational) :} If f(x) is periodic function, then:

    A
    either `K_1, K_2in rational or K_1, K_2 in irrational`
    B
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    C
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    D
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