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# inverse functions watch

1. h(x)= x^2-3, x<0
find the inverse of h(x)
my answer is √x+3 but why does the book say -√x+3
2. (Original post by man111111)
h(x)= x^2-3, x<0
find the inverse of h(x)
my answer is √x+3 but why does the book say -√x+3
3. (Original post by Kevin De Bruyne)
thanks for replying but im still not sure
4. (Original post by man111111)
h(x)= x^2-3, x<0
find the inverse of h(x)
my answer is √x+3 but why does the book say -√x+3
Because if we say for then hence the inv. function is . Now we need to choose the sign. Note that the domain of is now in fact the range of . So, the range of the inverse must be , thus we require that and this is only possible when we the -ve sign in front of the root.
5. (Original post by RDKGames)
Because if we say for then hence the inv. function is . Now we need to choose the sign. Note that the domain of is now in fact the range of . So, the range of the inverse must be , thus we require the -ve sign in front of the root.
oh okay thanks for your help

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Updated: February 11, 2018
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