how to do (4-4x+X^2)/2-X
y=lim x-1
thank you!

Question

how to do (4-4x+X^2)/2-X
y=lim x->1
thank you!

anonymous · Answer

4 - 4x - x^2 = (2 - x)^2; cancel with the (2 - x) from the denominator and get limit x ->1 of (2 - x) which is 1.

kelly · Answer

thank Lilian! I just plug 1 into all the X and get the answer of 1 too. Do you think it is correct if i do the same thing on other similar questions like that?

anonymous · Answer

Well, the method can be applied but you have to be careful as some problems may require a bit of attention for the denominator. At first glance you may want to say that the limit is not defined when x = 2. But after you cancel the denominator, the situation change. So, use the same method but not with the same results.

anonymous · Answer

..I wanted to say that you cannot expect the same results.

kelly · Answer

so that best way to solve this kind of question is to cancel out the terms first?

anonymous · Answer

only if you can. There are situations and situations. You were lucky this time :)

kelly · Answer

what happened if the lim X->1+ then?

kelly · Answer

so i need to plug 1.1 into the X after cancel out all the terms?

anonymous · Answer

Yes. Reduce at much as you can and than work out.

kelly · Answer

you are so helpful Lilian, I have been seeking for help for a whole day, finally found someone can help me out with it. thank you!

kelly · Answer

if i put limit X->1+ for this question, will the answer going to be 1 or infinitive?