Draw the graph and find the domain and range for the functions:
(i) f(x) = x² - 1
(ii) f(x) = |x² - 1|
(iii) f(x) = |x - 1|
Don't forget to attach the graph! No incomplete answers are allowed.
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Answers
Answer:
{ R } ; { R } ; { R }.
Step-by-step explanation:
For f( x ) = x^2 - 1 :-
In functions we include on those function which have a real value( not imaginary ).
Therefore, we solve on the same basis.
In the given f( x ) we have x^2 - 1, which will always be a real number for all x ∈ R.
Thus, domain is ( ∞ , - ∞ ) or we say domain is { R } ( all real numbers ).
Let y = x^2 - 1
⇒ y = x^2 - 1 ⇒ y + 1 = x^2 ⇒ √( y + 1 ) = x
As x is a real number √( y + 1 ) must be a real number, for this y + 1 shouldn't be a -ve number ⇒ y + 1 ≥ 0 ⇒ y ≥ - 1.
Hence range of the given function is [ - 1 , ∞ ).
For f( x ) = | x^2 - 1 |
Domain( as in the above question ) is { R }.
Let y = | x^2 - 1 |
This will always be a +ve number. So range is [ 0 , ∞ ).
For f( x ) = | x - 1 |
A real-positive will be given( always ) for all real x(s). Therefore, domain is { R } and range is [ 0 , ∞ ).