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20 POINTS!!!

Let f(x)=1/x and g(x)=x^2-7x. what two numbers are NOT in the domain of f°g? separate your answes with a comma.

User Tim Bodeit
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1 Answer

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Hello from MrBillDoesMath!

Answer:

x = 0, 7

Discussion:

f(g(x)) =

f ( x^2-7x) =

1/ ( x^2 - 7x)


The points NOT in the domain are those where the denominator, x^2 - 7x = 0.

x^2 - 7x = 0 => factor x from each term

x(x-7) = 0 => one or both terms must each 0

x = 0 or x =7


Thank you,

MrB