Range and inverse of bijective functions

In summary, the conversation is discussing finding the range and inverse for two bijective functions. The first function is f(x) = x² - 1 with a domain of all real numbers greater than or equal to 0. The range for this function is all real numbers greater than or equal to -1 and the inverse is x = √(y + 1). The second function is f(x) = (x + 1)² with a domain of all real numbers less than or equal to -2. The range for this function is all real numbers greater than or equal to 0 and the inverse is x = √y. Assistance is requested for finding the range of the first function and clarification on the range and
  • #1
MorallyObtuse
45
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Homework Statement


For each of the following bijective functions find the range S and the inverse:

a.) f : x |→ x² - 1 (x ∈ R, x ≥ 0)

b.) f : x |→ (x + 1)² ((x ∈ R, x ≤ -2)...Not sure how to do this one, help please

2. The attempt at a solution

a.) http://hotmath.com/images/gt/lessons/genericalg1/parabola.gif
the range (S) for the graph is (0,∞)
Inverse = x² - 1
x = √(y + 1)
 
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  • #2
Anybody able to help?
 
  • #3
MorallyObtuse said:

Homework Statement


For each of the following bijective functions find the range S and the inverse:

a.) f : x |→ x² - 1 (x ∈ R, x ≥ 0)

b.) f : x |→ (x + 1)² ((x ∈ R, x ≤ -2)...Not sure how to do this one, help please

2. The attempt at a solution

a.) http://hotmath.com/images/gt/lessons/genericalg1/parabola.gif
the range (S) for the graph is (0,∞)
Inverse = x² - 1
x = √(y + 1)[/QUOTE]
a) No, the range is NOT (0,∞). Are you clear on what range is? What is f(0)? Your graph is for y= x2, not y= x2- 1.

And you haven't completely described the inverse until you have told what its domain is.

b) x+1 is just x, "shifted over 1". Do you know what the range of x2 is?
 
  • #4
The range is the set of output numbers of a function. f(0) would be -1
The domain is the set of inputs for a function.

The range of x2 is 0 or and postive R.
 
  • #5
Someone able to help?
 

FAQ: Range and inverse of bijective functions

What is the definition of a bijective function?

A bijective function is a type of mathematical function that has a one-to-one correspondence between its input and output. This means that for every input, there is a unique output and vice versa.

How can you determine if a function is bijective?

A function can be determined as bijective if it is both injective (one-to-one) and surjective (onto). This means that every element in the output has a corresponding element in the input, and each input has a unique output.

What is the range of a bijective function?

The range of a bijective function is the set of all possible output values of the function. This means that every output value can be achieved by at least one input value.

How is the inverse of a bijective function calculated?

The inverse of a bijective function is calculated by switching the input and output variables of the original function. This means that the input of the original function becomes the output of the inverse function, and vice versa.

Why is the inverse of a bijective function important?

The inverse of a bijective function is important because it allows us to solve for the original input value given an output value. This can be useful in many real-world applications, such as finding the original price of a discounted item or determining the initial value of an investment based on its final value.

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