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Inverses of Functions. Warm Up #1 – Find the following. Answer to a. Answer to b. Answer to c. Answer to d. Answer to e. Answer to f. Answer to g. Warm Up #2 - Determine whether the statement is true or false. Justify your answer. FALSE!.
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Warm Up #2 - Determine whether the statement is true or false. Justify your answer. FALSE!
Warm Up #3: Graph & give the domain & range. Answer on Next Slide
Warm Up #3: Graph & give the domain & range. x y x -3 -4 -5 2 1 0 1 2 3 4 -3 -2 -1 0
Inverse of a relation • The inverse of the ordered pairs (x, y) is the set of all ordered pairs (y, x). • The Domain of the function is the range of the inverse and the Range of the function is the Domain of the inverse. • Symbol: In other words, switch the x’s and y’s!
Function notation? What is really happening when you find the inverse? Find the inverse of f(x)=4x-2 *4 -2 x 4x-2 (x+2)/4 /4 +2 x So
To find an inverse… • Switch the x’s and y’s. • Solve for y. • Change to functional notation.
Draw the inverse. Compare to the line y = x. What do you notice?
Graph the inverse of the following: The function and its inverse are symmetric with respect to the y-axis. x y 0 -3 1 1 -5 -4 2 4
Things to note.. • The domain of is the range of f(x). • The graph of an inverse function can be found by reflecting a function in the line y=x. Check this by plotting y = 3x + 1 and on your graphic calculator. Take a look
Find the inverse of the function. Is the inverse also a function? Let’s look at the graphs. NOTE: Inverse is NOT a function! Inverse
Horizontal Line Test • If a horizontal line only passes through one point at a time, then the inverse of the function will also be a function.
Composition and Inverses • If f and g are functions and then f and g are inverses of one another. !!!!!!!!!!!!!!!!!!!!!!
Example: Show that the following are inverses of each other. The composition of each both produce a value of x; Therefore, they are inverses of each other.
You Try…. • Show that • are inverses of each other.