1) Draw a picture (or use the grapher). the graph for x from 0 to 3 looks like an arc, symmetric about identity, or line y=x.
This is an important clue.
2) do the usual:
y = sqrt(9-x^2), interchange x and y
x = sqrt(9-y^2), solve for y
x^2 = 9-y^2, so
y^2 = 9-x^2 or
y = sqrt(9-x^2).
No accident, this function is its own inverse, since it is symmetric about the identity. And yes, x is still from 0 to 3.
2007-07-27 18:31:09
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answer #1
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answered by Anonymous
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Given:
f(x) = ±â(9 - x^2), 0 ⤠x ⤠3, ( - 3 ⤠y ⤠3 )
Using y for f(x):
y = ±â(9 - x^2), 0 ⤠x ⤠3, - 3 ⤠y ⤠3
Swap x and y:
x = ±â(9 - y^2), 0 ⤠y ⤠3, - 3 ⤠x ⤠3
Expand:
x^2 = 9 - y^2, 0 ⤠y ⤠3, - 3 ⤠x ⤠3
y^2 = 9 - x^2, 0 ⤠y ⤠3, - 3 ⤠x ⤠3
Taking the root,
y = + â(9 - x^2), because 0 ⤠y ⤠3, - 3 ⤠x ⤠3
so
f^-1(x) = + â(9 - x^2), - 3 ⤠x ⤠3
2007-07-27 18:47:26
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answer #2
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answered by Helmut 7
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f(x)=square root of 9-x^2
lets f(x)=y
( 9-x^2)^1/2 = y
(9-x^2) = y^2
x^2 = 9-y^2
x= (9-y^2)^1/2
therefore, inverse of f(x) = (9-x^2)^1/2
answer: 1
2007-07-27 18:37:46
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answer #3
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answered by Clov 2
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f^-1 (x) is given by
x = sqrt(9-y^2)
x^2 = 9 - y^2
y^2 = 9 - x^2
y= +/- sqrt(9 - x^2)
but dom f = [0,3]
and range f = [0,3]
so dom f^-1 = [0,3], range f^-1 = [0,3],
so, f^-1(x) = sqrt(9 - x^2)
2007-07-27 18:32:54
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answer #4
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answered by Anonymous
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I can help you if you tell me the problem
2007-07-27 18:29:12
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answer #5
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answered by Johnny Handsome 2
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