English

Discuss the continuity of the function f(x) = |2x + 3|, at x = −32 - Mathematics and Statistics

Advertisements
Advertisements

Question

Discuss the continuity of the function f(x) = |2x + 3|, at x = `(−3)/(2)`

Sum

Solution

f(x) = |2x + 3|, x = `(−3)/(2)`

|2x + 3| = 2x + 3; `x ≥ (-3)/(2)`

= – (2x + 3); `x < (-3)/(2)`

`lim_(x -> (-3^(-))/(2)) "f"(x) = lim_(x -> (-3^(-))/(2)) |2x + 3|`

= `lim_(x -> (-3^(-))/(2)) [- (2x + 3)]`

= `-[2((-3)/2) + 3]`

= 0

`lim_(x -> (-3^(+))/(2)) "f"(x) = lim_(x -> (-3^(+))/(2)) |2x + 3|`

= `lim_(x -> (-3^(+))/(2)) (2x + 3)`

= `2 ((-3)/2) + 3`

= 0.

`"f"((-3)/2) = |2 ((-3)/2) + 3|`

= |0|

= 0

∴ `lim_(x -> (-3^(-))/(2)) "f"(x) = lim_(x -> (-3^(+))/(2)) "f"(x) = "f"((-3)/2)`

∴ f(x) is continuous at x = `(-3)/(2)`.

shaalaa.com
Continuous and Discontinuous Functions
  Is there an error in this question or solution?
Chapter 8: Continuity - EXERCISE 8.1 [Page 172]

RELATED QUESTIONS

Examine whether the function is continuous at the points indicated against them:
f(x) = `(x^2 + 18x - 19)/(x - 1)`        for x ≠ 1

      = 20                               for x = 1, at x = 1


Examine whether the function is continuous at the points indicated against them:

f(x)  `{:(= x^3 - 2x + 1",",  "if"  x ≤ 2),(= 3x - 2",",  "if"  x > 2):}}` at x = 2


Examine whether the function is continuous at the points indicated against them :

f(x) `{:( = (x^2 + 18x - 19)/(x - 1)",",  "for"  x ≠ 1),(= 20",",  "for"  x = 1):}}` at x = 1


Test the continuity of the following function at the point or interval indicated against them :

f(x)  `{:(= (sqrt(x - 1) - (x - 1)^(1/3))/(x - 2)",",  "for"  x ≠ 2),(= 1/5",",  "for"  x = 2):}}`at x = 2


Test the continuity of the following function at the point or interval indicated against them :

f(x)  `{:(= (x^3 - 8)/(sqrt(x + 2) - sqrt(3x - 2))",",  "for"  x ≠ 2),(= -24",",  "for"  x = 2):}}` at x = 2


Test the continuity of the following function at the point or interval indicated against them :

f(x) `{:(= 4x + 1",",  "for"  x ≤  8/3),(= (59 - 9x)/3 ",",  "for"  x > 8/3):}}  "at"  x = 8/3`


Identify discontinuities for the following function as either a jump or a removable discontinuity :

f(x) = `(x^2 - 10x + 21)/(x - 7)`


Identify discontinuities for the following function as either a jump or a removable discontinuity :

f(x) `{:(= x^2 - 3x - 2",",  "for"  x < -3),(= 3 + 8x",",  "for"  x > -3):}`


Identify discontinuities for the following function as either a jump or a removable discontinuity :

f(x) `{:(= 4 + sin x",",  "for"  x < pi),(= 3 - cos x",",  "for"  x > pi):}`


Discuss the continuity of the following function at the point indicated against them :

f(x) = `{:(=( sqrt(3) - tanx)/(pi - 3x)",", x ≠ pi/3),(= 3/4",", x = pi/3):}}  "at"  x = pi/3`


Discuss the continuity of the following function at the point indicated against them :

f(x)  `{:(=("e"^(1/x) - 1)/("e"^(1/x) + 1)",",  "for"  x ≠ 0),(= 1",", "for"  x = 0):}}` at x = 0


Discuss the continuity of the following function at the point indicated against them :

f(x)  `{:(=(4^x - 2^(x + 1) + 1)/(1 - cos 2x)",",  "for"  x ≠ 0),(= (log 2)^2/2",",  "for"  x = 0):}}` at x = 0.


The following function has a removable discontinuity? If it has a removable discontinuity, redefine the function so that it become continuous :

f(x) `{:(= log_((1 + 3x)) (1 + 5x)",", "for"  x > 0),(=(32^x - 1)/(8^x - 1)",",  "for"  x < 0):}}` at x = 0


If f(x) = `(sqrt(2 + sin x) - sqrt(3))/(cos^2x), "for"  x ≠ pi/2`, is continuous at x = `pi/2` then find `"f"(pi/2)`


If f(x) = `(cos^2 x - sin^2 x - 1)/(sqrt(3x^2 + 1) - 1)` for x ≠ 0, is continuous at x = 0 then find f(0)


If f(x) = `(4^(x - π) + 4^(π - x) - 2)/(x - π)^2` for x ≠ π, is continuous at x = π, then find f(π).


If f(x) `{:(= (24^x - 8^x - 3^x + 1)/(12^x - 4^x - 3^x + 1)",",  "for"  x ≠ 0), (= "k"",",  "for"  x = 0):}}` is continuous at x = 0, find k


For what values of a and b is the function

f(x) `{:(= "a"x + 2"b" + 18",",  "for"  x ≤ 0),(= x^2 + 3"a" - "b"",",  "for"  0 < x ≤ 2),(= 8x - 2",",  "for"  x > 2):}}` continuous for every x?


For what values of a and b is the function

f(x) `{:(= (x^2 - 4)/(x - 2)",", "for"  x < 2),(= "a"x^2 - "b"x + 3",", "for"  2 ≤ x < 3),(= 2x - "a" + "b"",", "for"  x ≥ 3):}}` continuous for every x on R?


Discuss the continuity of f(x) at x = `pi/4` where, 

f(x) `{:(= ((sinx + cosx)^3 - 2sqrt(2))/(sin 2x - 1)",", "for"  x ≠ pi/4),(= 3/sqrt(2)",", "for"  x = pi/4):}`


Show that there is a root for the equation x3 − 3x = 0 between 1 and 2.


Select the correct answer from the given alternatives:

If f(x) = [x] for x ∈ (–1, 2) then f is discontinuous at


Discuss the continuity of the following function at the point(s) or on the interval indicated against them:

f(x) `{:(= 2x^2 - 2x + 5",", "for"  0 ≤ x ≤ 2),(= (1 - 3x - x^2)/(1 - x) "," , "for"  2 < x < 4),(= (x^2 - 25)/(x - 5)",", "for"  4 ≤ x ≤ 7 and x ≠ 5),(= 7",", "for"  x = 5):}`


Discuss the continuity of the following function at the point(s) or on the interval indicated against them:

f(x) `{:(= 2x^2 + x + 1",", "for"  |x - 3| ≥ 2),(= x^2 + 3",", "for"  1 < x < 5):}`


Identify discontinuity for the following function as either a jump or a removable discontinuity on their respective domain:

f(x) `{:(= (x^2 + x + 1)/(x + 1)"," , "for"  x ∈ [0, 3)),(=(3x +4)/(x^2 - 5)"," , "for"  x ∈ [3, 6]):}`


Discuss the continuity of the following function at the point or on the interval indicated against them. If the function is discontinuous, identify the type of discontinuity and state whether the discontinuity is removable. If it has a removable discontinuity, redefine the function so that it becomes continuous:

f(x) = `((x + 3)(x^2 - 6x + 8))/(x^2 - x - 12)`


Find k if following function is continuous at the point indicated against them:

f(x) `{:(= (45^x - 9^x - 5^x + 1)/(("k"^x - 1)(3^x - 1))",", "for"  x ≠ 0),(= 2/3",", "for"  x = 0):}}` at x = 0


Find a and b if following function is continuous at the point or on the interval indicated against them:

f(x) `{:(= "a"x^2 + "b"x + 1",", "for"  |2x - 3| ≥ 2),(= 3x + 2",", "for"  1/2 < x < 5/2):}`


Find f(a), if f is continuous at x = a where,

f(x) = `(1 - cos[7(x - pi)])/(5(x - pi)^2`, for x ≠ π at a = π


Solve using intermediate value theorem:

Show that x3 − 5x2 + 3x + 6 = 0 has at least two real root between x = 1 and x = 5


If f(x) is continuous at x = 3, where

f(x) = ax + 1, for x ≤ 3

= bx + 3, for x > 3 then.


Let f : [-1, 2] → [0, ∞] be a continuous function such that f(x) = f(1 - x) ∀ x ∈ [-1, 2].

Let R1 = `int_-1^2 xf(x) dx` and R2 be the area of the region bounded by y = f(x), x = -1, x = 2 and the X-axis. Then, ______


`lim_(x rightarrow 0) (e^(x^2) - cosx)/x^2` is equal to ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×