Hey
i've just been trying to work out this limit
its been hours and my tutor rekons its just - infinite
i've tried dividing all by x cubed, factorizing and trying to cancel, multiplying but the conjugant and messing around with it
here it is
(lim as x approaches -3 from the right)
lim 5x^2/ x^2 + 2x - 3
x->-3+
Thanks in advance
What you should have seen immediately is that the numerator, does not go to 0 at x= -3. Since the denominator does, that alone is enough to tell you that the limit does not exist and all your " dividing all by x cubed, factorizing and trying to cancel, multiplying by the conjugant and messing around with it" is useless. Saying it goes to is just saying it does not exist for a particular reason- and you can see that by looking at the graph or by evaluating the function at, say, -2.9.