SOLUTION: use g(x)=5/(1-2x) and f(x)=1-x^2 find f(-5) find the domain of g(x)

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Question 127841: use g(x)=5/(1-2x) and f(x)=1-x^2

find f(-5)

find the domain of g(x)
Answer by solver91311(24713) About Me  (Show Source):
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A word about function notation. f or g or h is a function. f(x) is the value of the function f at x, g(a) is the value of the function g at a.
If f%28x%29=1-x%5E2, then 1-x%5E2 is the value of the function f at x, so f(-5) is the value of the function at -5, i.e. f%28-5%29=1-%28-5%29%5E2. You do the arithmetic.

The domain of a function is the set of values for which the function is defined. The given function g is a rational expression that is defined everywhere except where the denominator is zero. So, if 1-2x=0, then g is not defined.

1-2x=0

-2x=-1

x=1%2F2

So the domain of g is all real numbers except 1%2F2. In interval notation:

(-infinity,1%2F2) U (1%2F2,infinity)

In set notation {x|x is real, x%3C%3E1%2F2}