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Calling all Calculus Whizzes
I've got a prob that isn't necessarilly difficult, but deal more with concepts than real numbers and I just can't get it. I'll try to write it out as best I can.
Define f,g : R -> R be functions such that:
lim f(x) (as x approaches 0) = a a does not equal 0
lim g(x) (as x approaches 0) = 0
Prove that: lim (as x approaches 0) f(x)/g(x) cannot exist as a real number.
Then, let f:R->R be a function and b in the real number line such that f is NOT continuous a b. Use the previous problem to show that f is NOT differentiable at b.
Got all that?
The first part seemed rather simple...the limit (as x approaches 0) of f(x)/g(x)= a/0, where a does not equal 0. You cannot divide any real number by zero and obtain a real number. But beyond that...things are just out of grasp for me it seems. Any input would be appreciated while I sit here scratching my head. Thanks.
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