English

Evaluate the following : limx→0[(1-x)5-1(1-x)3-1] - Mathematics and Statistics

Advertisements
Advertisements

Question

Evaluate the following :

`lim_(x -> 0)[((1 - x)^5 - 1)/((1 - x)^3 - 1)]`

Sum

Solution

`lim_(x -> 0)[((1 - x)^5 - 1)/((1 - x)^3 - 1)]`

Put 1 – x = y

As x → 0, y → 1

∴ `lim_(x -> 0)[((1 - x)^5 - 1)/((1 - x)^3 - 1)]`

= `lim_(y -> 1) (y^5 - 1)/(y^3 - 1)`

= `(lim_(y -> 1) (y^5 - 1)/(y - 1))/(lim_(y -> 1)(y^3 - 1)/(y - 1))`   ...[∵ y → 1, ∴ y ≠ 1, ∴ y – 1 ≠ 0]

= `(lim_(y  -> 1)(y^5 - 1^5)/(y - 1))/(lim_(y -> 1)(y^3 - 1^3)/(y - 1))`

= `(5(1)^4)/(3(1)^2)    ...[lim_(x -> "a") (x^"n" - "a"^"n")/(x - "a") = "na"^("n" - 1)]`

= `5/3`  

shaalaa.com
Substitution Method
  Is there an error in this question or solution?
Chapter 7: Limits - Miscellaneous Exercise 7.2 [Page 159]

APPEARS IN

Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×