मराठी

Let f: R – {–4/3} → R be a function defined as f(x) = (4x)/(3x + 4). The inverse of f is map g: Range f → R – {–4/3} given by

Advertisements
Advertisements

प्रश्न

Let `f: R - {-4/3} → R` be a function defined as `f(x) = (4x)/(3x + 4)`. The inverse of f is map g: Range `f → R - {-4/3}` given by

पर्याय

  • `g(y) = (3y)/(3 - 4y)`

  • `g(y) = (4y)/(4 - 3y)`

  • `g(y) = (4y)/(3 - 4y)` 

  • `g(y) = (3y)/(4 - 3y)`

MCQ
Advertisements

उत्तर

`bb(g(y) = (4y)/(4 - 3y))`

Explanation:

It is given that `f: R -{-4/3} → R` is defined as `f(x) = (4x)/(3x - 4)`.

Let y be an arbitrary element of Range f.

Then, there exists `x ∈ R - {-4/3}` such that y = f(x).

⇒ `y = (4x)/(3x +  4)`

⇒ 3xy + 4y = 4x 

⇒ x(4 – 3y) = 4y

⇒ `x = (4y)/(4 - 3y)`

Let us define g: Range `f → R -{-4/3}` as `g(y) = (4y)/(4 - 3y)`.

Now, (gof)(x) = g(f(x)) 

= `g((4x)/(3x + 4))`

= `(4((4x)/(3x + 4)))/(4 - 3((4x)/(3x + 4)))` 

= `(16x)/(12x + 16 - 12x)` 

= `(16x)/16`

= x

And (fog)(y) = f(g(y)) 

= `f((4y)/(4 - 3y))`

= `(4((4y)/(4 - 3y)))/(3((4y)/(4 - 3y)) + 4)`

= `(16y)/(12y + 16 - 12y)`

= `(16y)/16`

= y

∴ `gof = I_(R - {-4/3})` and `fog = I_"Range f"`

Thus, g is the inverse of f i.e., f−1 = g.

Hence, the inverse of f is the map g: Range `f → R - {-4/3}`, which is given by `g(y) = (4y)/(4 - 3y)`.

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 1: Relations and Functions - EXERCISE 1.3 [पृष्ठ १९]

APPEARS IN

एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
पाठ 1 Relations and Functions
EXERCISE 1.3 | Q 14. | पृष्ठ १९

व्हिडिओ ट्यूटोरियलVIEW ALL [4]

संबंधित प्रश्‍न

If the function f : R → R be defined by f(x) = 2x − 3 and g : R → R by g(x) = x3 + 5, then find the value of (fog)−1 (x).


Let f : W → W be defined as

`f(n)={(n-1, " if n is odd"),(n+1, "if n is even") :}`

Show that f is invertible a nd find the inverse of f. Here, W is the set of all whole
numbers.


Let f: {1, 3, 4} → {1, 2, 5} and g: {1, 2, 5} → {1, 3} be given by f = {(1, 2), (3, 5), (4, 1)} and g = {(1, 3), (2, 3), (5, 1)}. Write down gof.


If `f(x) = (4x + 3)/(6x - 4), x ≠ 2/3` show that fof(x) = x, for all `x ≠ 2/3`. What is the inverse of f?


State with reason whether following functions have inverse 

h: {2, 3, 4, 5} → {7, 9, 11, 13} with h = {(2, 7), (3, 9), (4, 11), (5, 13)}


Show that f: [–1, 1] → R, given by f(x) = `x/(x + 2)`  is one-one. Find the inverse of the function f: [–1, 1] → Range f.

(Hint: For y in Range f, y = `f(x) = x/(x + 2)` for some x in [–1, 1] i.e., `x = (2y)/(1 - y)`)


Consider f: R→ [4, ∞) given by f(x) = x2 + 4. Show that f is invertible with the inverse f−1 of given f by `f^(-1)(y) = sqrt(y - 4)`, where R+ is the set of all non-negative real numbers.


Let f: X → Y be an invertible function. Show that f has unique inverse. (Hint: suppose g1 and g2 are two inverses of f. Then for all y ∈ Y, fog1(y) = IY(y) = fog2(y). Use one-one ness of f).


Consider f: {1, 2, 3} → {a, b, c} given by f(1) = a, f(2) = b and f(3) = c. Find f−1 and show that (f−1)−1 = f.


If f: R → R be given by `f(x) = (3 - x^3)^(1/3)`, then fof(x) is ______.


Let f: W → W be defined as f(n) = n − 1, if is odd and f(n) = n + 1, if n is even. Show that f is invertible. Find the inverse of f. Here, W is the set of all whole numbers.


Consider f: `R_+ -> [-5, oo]` given by `f(x) = 9x^2 + 6x - 5`. Show that f is invertible with `f^(-1) (y) ((sqrt(y + 6)-1)/3)`

Hence Find

1) `f^(-1)(10)`

2) y if `f^(-1) (y) = 4/3`

where R+ is the set of all non-negative real numbers.


Let f : W → W be defined as f(x) = x − 1 if x is odd and f(x) = x + 1 if x is even. Show that f is invertible. Find the inverse of f, where W is the set of all whole numbers.


If f : R → R, f(x) = x and g: R → R , g(x) =  2x+ 1, and R is the set of real numbers, then find fog(x) and gof (x)


Let f: R → R be defined by f(x) = 3x 2 – 5 and g: R → R by g(x) = `x/(x^2 + 1)` Then gof is ______.


Let f: A → B and g: B → C be the bijective functions. Then (g o f)–1 is ______.


Let f: [0, 1] → [0, 1] be defined by f(x) = `{{:(x",",  "if"  x  "is rational"),(1 - x",",  "if"  x  "is irrational"):}`. Then (f o f) x is ______.


Let f: N → R be the function defined by f(x) = `(2x - 1)/2` and g: Q → R be another function defined by g(x) = x + 2. Then (g o f) `3/2` is ______.


Let f: R → R be the function defined by f(x) = sin (3x+2) ∀ x ∈ R. Then f is invertible.


Every function is invertible.


Let f : N → R : f(x) = `((2"x"−1))/2` and g : Q → R : g(x) = x + 2 be two functions. Then, (gof) `(3/2)` is ____________.


If f : R → R, g : R → R and h : R → R are such that f(x) = x2, g(x) = tan x and h(x) = log x, then the value of (go(foh)) (x), if x = 1 will be ____________.


If f(x) = `(3"x" + 2)/(5"x" - 3)` then (fof)(x) is ____________.


If f(x) = (ax2 – b)3, then the function g such that f{g(x)} = g{f(x)} is given by ____________.


The inverse of the function `"y" = (10^"x" - 10^-"x")/(10^"x" + 10^-"x")` is ____________.


Consider the function f in `"A = R" - {2/3}` defiend as `"f"("x") = (4"x" + 3)/(6"x" - 4)` Find f-1.


If f is an invertible function defined as f(x) `= (3"x" - 4)/5,` then f-1(x) is ____________.


A general election of Lok Sabha is a gigantic exercise. About 911 million people were eligible to vote and voter turnout was about 67%, the highest ever


Let I be the set of all citizens of India who were eligible to exercise their voting right in the general election held in 2019. A relation ‘R’ is defined on I as follows:

R = {(V1, V2) ∶ V1, V2 ∈ I and both use their voting right in the general election - 2019}

  • Two neighbors X and Y ∈ I. X exercised his voting right while Y did not cast her vote in a general election - 2019. Which of the following is true?

The domain of definition of f(x) = log x2 – x + 1) (2x2 – 7x + 9) is:-


Let A = `{3/5}` and B = `{7/5}` Let f: A → B: f(x) = `(7x + 4)/(5x - 3)` and g:B → A: g(y) = `(3y + 4)/(5y - 7)` then (gof) is equal to


If f: A → B and G B → C are one – one, then g of A → C is


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×