Find any points of discontinuity for the rational function.
Just remember, rational functions are always continuous on their domain.
So if you're to find points of discontinuity, it had best not be in the domain of your function :) For what values of x does your function NOT have a defined value?
See, for instance, if your function takes x = -7, then your denominator becomes zero, which cannot yield a defined value. There is another value for x which would make the denominator zero.
x = –9, x = –7??
Right... As you can see, the denominator has a factor of (x + 9) The entire denominator is (x + 9)(x + 7) If x = -7, the denominator becomes (2)(0) = 0 Which means x cannot be -7. If x = -9, the denominator becomes (0)(-2) = 0 Which means x cannot be -9. Every other value of x is acceptable, hence the function is continuous on every other value of x. Hence, it is discontinuous at x = -7 and x = -9 :)
Well, that's about it. NOTE I said something about "Every other value of x is acceptable, hence the function is continuous on every other value of x" This is only true because this is a rational function, which can be shown to be continuous on its domain. Since all other values of x are acceptable, all other values of x are in its domain, and the function is therefore continuous on said values of x. Got that? That was a mouthful XD That's it for now... --- Terence out
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