limit of any function is the value of neighboring hood pt. so i directly substitute the value of limit in the functon lim x tend to 3(3x^2-4x-10) = 5 what does it mean i wanna kno why some limits can be found by direct substitution and some by using other formulae...

Dear himank

If the function is define at that point in which point u are finding the limit then u can find it directlt as an example given by u

x=3 is in the domain of function 3x^2-4x-10  so u can find by direct .

but if the function is not define at the point where u are finding the limit then u can't use the direct method

such as   f(x) = (x²-x )/x   tis function is not define at x=0

 so u can't find limit by just direct putting.

      in this case u have to take common x and then u can put the value x=0

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