हिंदी

Let f: R → R be defined by f(x) = 3x 2 – 5 and g: R → R by g(x) = xx2+1 Then gof is ______

Advertisements
Advertisements

प्रश्न

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 ______.

विकल्प

  • `(3x^2 - 5)/(9x^4 - 30x^2 + 26)`

  • `(3x^2 - 5)/(9x^4 - 6x^2 + 26)`

  • `(3x^2)/(x^4 + 2x^2 - 4)`

  • `(3x^2)/(9x^4 + 30x^2 - 2`

MCQ
रिक्त स्थान भरें
Advertisements

उत्तर

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 `(3x^2 - 5)/(9x^4 - 30x^2 + 26)`.

Explanation:

Given that, f(x) = 3x2 – 5 and g(x) = `x/(x^2 + 1)`

gof(x) = g(f(x))

= g(3x2 – 5)

= `(3x^2 - 5)/((3x^2 - 5)^2 + 1)`

= `(3x^2 - 5)/(9x^4 - 30x^2 + 25 + 1)`

= `(3x^2 - 5)/(9x^4 - 30x^2 + 26)`

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 1: Relations And Functions - Exercise [पृष्ठ १५]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 12
अध्याय 1 Relations And Functions
Exercise | Q 38 | पृष्ठ १५

वीडियो ट्यूटोरियलVIEW ALL [4]

संबंधित प्रश्न

Find gof and fog, if f(x) = 8x3 and `g(x) = x^(1/3)`.


State with reason whether following functions have inverse 

g: {5, 6, 7, 8} → {1, 2, 3, 4} with g = {(5, 4), (6, 3), (7, 4), (8, 2)}


Consider f: R → R given by f(x) = 4x + 3. Show that f is invertible. Find the inverse of f.


Consider f: R+ → [–5, ∞) given by f(x) = 9x2 + 6x – 5. Show that f is invertible with `f^(-1)(y) = ((sqrt(y + 6) - 1)/3)`.


Let f: X → Y be an invertible function. Show that the inverse of f−1 is f, i.e., (f−1)−1 = f.


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


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) = x3  and g: R → R , g(x) =  2x2 + 1, and R is the set of real numbers, then find fog(x) and gof (x)


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


The composition of functions is commutative.


Every function is invertible.


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


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 ____________.


Let f : R → R be the functions defined by f(x) = x3 + 5. Then f-1(x) is ____________.


Let f : R – `{3/5}`→ R be defined by f(x) = `(3"x" + 2)/(5"x" - 3)` Then ____________.


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 ____________.


Domain of the function defined by `f(x) = 1/sqrt(sin^2 - x) log_10 (cos^-1 x)` is:-


A function \(f:X\to Y\) is defined to be invertible if there exists a function \(g:Y\to X\) such that which conditions hold?


A function that is both one-one and onto is called what?


What is the necessary and sufficient condition for a function to be invertible?


Which property of inverse functions is represented by \((f^{-1})^{-1}=f\)?


If \(f:A\to B\) and \(g:B\to C\) are both bijections, which statement is the Reversal Law of Inverses?


According to the Reflective Property, the graph of \(f^{-1}\) is the exact reflection of the graph of \(f\) across which line?


Which pair consists of examples of self-inverse functions?


For \(f(x)=4x+3\), where \(Y=\{y\in\mathbb{N}:y=4x+3\text{ for some }x\in\mathbb{N}\}\), what is the inverse function \(g:Y\to\mathbb{N}\)?


In the graphical example, what are the domain and range of the given function?


Which statement expresses that an inverse is unique whenever it exists?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×