Composite And Inverse Functiond Flashcards
What’s a function
Is an operation that takes numbers and maps each one to only one number.
f(x) = x^2
f : x -> x^2
Set of starting big numbers are called ___ in functions and the numbers they become is the ______ or ______
Domain
Range or image
If x can take any real value it’s usually written
x E R
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One to one function
Maps one element in the domain to one element in the range
A many to one function
Maps more than one element in the domain to one element in the range
One to many mapping’s can
Take an element in the domain to more than one element in the range
By definition it’s not a function
Functions can be combined
This is called a composite function.
Written fg(x) this means do g first then f
If you get f^2(x) it means ff(x)
Which functions have inverses?
One to one functions only.
What is an inverse function
It does the opposite of the function, it maps and element in the range to an element in the domain.
F^-1f(x)
The domain of the inverse is the range of the function.
Calculating an inverse function
Make f(x) to y
Then make x the subject of the equation
Replace y with x and x with f^-1(x)
Swap the domain and the range
To find range of function from domain put smallest number of domain into function…
Inverse function so inverse the domain to become range of inverse function…
You might have to draw the graph of the inverse
The inverse of a function is its reflection in the line x=y