Question 12594: if f(x)=x^2-7x+3 and g(x)= x+1/x-3, find the domain of g o f. thanks
Answer by longjonsilver(2297)   (Show Source):
You can put this solution on YOUR website! i am assuming that g(x) =  ?
well, gf(x) would then be  where th edenominator factorises to x(x-7)
So, the domain of this? The domain is "what are the possible x-values i can put in?". Well seeing as how you have given no domain definition for either f(x) or g(x), i will assume that any real value goes, so...
look at the denominator here. What values of x make the fraction go do-lally? The thing you are looking for is any value of x such that the denominator is ZERO, since anything/zero will give an error.
well, we have x(x-7), so either x=0 or x=7 will make the denominator zero, so these 2 values are NOT allowed.
So, domain is xeR, but not 0 or 7.
Need to clarify with your teacher too, if the x=3 from the x-3 of g(x) will be carried over to the composite gf(x) function.
jon.
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