Home
Class 12
MATHS
Let f,g: RvecR be a two function define...

Let `f,g: RvecR` be a two function defined as `f(x)=|x|+x and g(x)=|x|-x` for all `x in Rdot` Then, find `fog` and `gof`

Text Solution

Verified by Experts

`f(x)=2 x, text { if } x geq 0 , text { if } quad x<0.`

`g(x)=0, text { if } quad x geq 0 -2 x, text { if } x<0.`

Thus for `x geq 0, quad` (gof) `(x)=g(2 x)=0`

and for `x<0, quad(g o f)(x)=g(0)=0`

or `(g circ f)(x)=0 forall x in R` Thus for `x geq 0, quad(` fog `)(x)=f(0)=2(0)=0`

and for `x<0, quad(f circ g)(x)=f(-2 x)=-4 x`

or

...
Promotional Banner

Topper's Solved these Questions

  • DIRECTION COSINES AND DIRECTION RATIOS

    RD SHARMA|Exercise Solved Examples And Exercises|67 Videos
  • HIGHER ORDER DERIVATIVES

    RD SHARMA|Exercise Solved Examples And Exercises|176 Videos

Similar Questions

Explore conceptually related problems

Let f,g:R rarr R be two functions defined as f(x)=|x|+x and g(x)=|x|-x, for all x in R. Then find fog and gof.

If f,g:R rarr R be two functions defined as f(x)=|x|+x and g(x)=|x|-x. Find fog and gof.Hence find fog(-3), fog (5) and gof(-2).

Let f and g be two functions from R into R defined by f(x) =|x|+x and g(x) = x " for all " x in R . Find f o g and g o f

Find gof and fog, if f(x)=|x| and g(x)=|5x-2|

If f: R->R and g: R->R be functions defined by f(x)=x^2+1 and g(x)=sinx , then find fog and gof .

Let f: R->R , g: R->R be two functions defined by f(x)=x^2+x+1 and g(x)=1-x^2 . Write fog\ (-2) .

Let f,g:vec R be defined by f(x)=2x+1 and g(x)=x^(2)-2 for all x in R, respectively.Then,find gof

If f(x)=sqrt(x+3) and g(x)=x^2+1 be two real functions, then find fog and gof .

If f: R to R and g: R to R be two functions defined as f(x)=2x+1 and g(x)=x^(2)-2 respectively , then find (gof) (x) and (fog) (x) and show that (fog) (x) ne (gof) (x).

If f: R to R and g: R to R be two functions defined as f(x)=x^(2) and g(x)=5x where x in R , then prove that (fog)(2) ne (gof) (2).

RD SHARMA-FUNCTION-Solved Examples And Exercises
  1. If f:(-pi/2,pi/2)-&gt;R and g:[-1,1]-&gt;R be defined as f(x)=tanx a...

    Text Solution

    |

  2. If f(x)=sin^2x+sin^2(x+pi/3)+cosxcos(x+pi/3)a n dg(5/4)=1, then (gof)...

    Text Solution

    |

  3. Let f,g: RvecR be a two function defined as f(x)=|x|+x and g(x)=|x|-x...

    Text Solution

    |

  4. Let A={a,b,c,d} and f :A->A be given by f={(a,b),(b,d),(c,a),(d,c)} , ...

    Text Solution

    |

  5. Let f={(3,1),(9,3),(12 ,4)} and g={(1,3),(3,3),(4,9),(5,9)}dot Show th...

    Text Solution

    |

  6. If F :[1,oo)vec[2,oo) is given by f(x)=x+1/x ,t h e nf^(-1)(x) equal...

    Text Solution

    |

  7. Let f: RrarrR and g: RrarrR be two functions such that fog(x)=sin...

    Text Solution

    |

  8. Let R be the set of real numbes. If f: RvecR ;f(x)=x^2 and g: RvecR ;g...

    Text Solution

    |

  9. If f(x)=-4-(x-7)^3 , write f^(-1)(x)dot

    Text Solution

    |

  10. If f:{5,6}vec{2,3}a n dg:{2,3}vec{5,6} are given by f={(5,2),(6,3)} an...

    Text Solution

    |

  11. If a function g={(1,1),(2,3),(3,5),(4,7)} is described by g(x)=alphax+...

    Text Solution

    |

  12. Show that f: R-[0]vecR0[0] given by f(x)=3/x is invertible and it is i...

    Text Solution

    |

  13. Let A={1,2,..., n} and B={a , b }. Then number of surjections from A...

    Text Solution

    |

  14. If f: Rvec(-1,1) is defined by f(x)=-(x|x|)/(1+x^2),t h e nf^(-1)(x) e...

    Text Solution

    |

  15. Let f: ZvecZ be defined by f(n)=3n for all n in Z and g: Zvec be defi...

    Text Solution

    |

  16. Let A={x in R :0lt=xlt=1}dot If f: AvecA is defined by f(x)={x ,ifx Q...

    Text Solution

    |

  17. Let A=[-1,1]dot Then, discuss whether the following functions from A t...

    Text Solution

    |

  18. Let R be a relation on the set A of ordered pairs of positive integ...

    Text Solution

    |

  19. Let A be a finite set. If f: AvecA is an onto function, show that f is...

    Text Solution

    |

  20. Show that the function f: R-{3}->R-{1} given by f(x)=(x-2)/(x-3) is ...

    Text Solution

    |