Let f(x)= (2x^2 + 5x - 18) / (x - 2)
Show that f(x) has a removable discontinuity at x=2 and determine what value for f(2) would make f(x) continuous at x=2.
Must define f(2)=?
How do I do this problem? Can't figure out how to set it up.
And I'm sure this one is similar:
let f(x)=
x^2 + 10x + 30, if x< - 5
-2, if x= - 5
-x^2 - 10x - 20, if x> - 5
Show that f(x) has a removable discontinuity at x= - 5 and determine what value for f( - 5) would make f (x) continuous at x= - 5.
Must redefine f( - 5)=?
I don't want the answers; that won't help me at all. I want to know how to do them. Thanks!
Show that f(x) has a removable discontinuity at x=2 and determine what value for f(2) would make f(x) continuous at x=2.
Must define f(2)=?
How do I do this problem? Can't figure out how to set it up.
And I'm sure this one is similar:
let f(x)=
x^2 + 10x + 30, if x< - 5
-2, if x= - 5
-x^2 - 10x - 20, if x> - 5
Show that f(x) has a removable discontinuity at x= - 5 and determine what value for f( - 5) would make f (x) continuous at x= - 5.
Must redefine f( - 5)=?
I don't want the answers; that won't help me at all. I want to know how to do them. Thanks!
-
(2x^2 + 5x - 18) / (x - 2)
= (x-2)(2x+9)/(x-2)
= 2x+9
if x=2, 2x+9=13
define f(2)=13 to make it continuous
--------------------------------------…
lim x-->-5- f(x) = (-5)^2 +10(-5) + 30 = 5
lim x-->-5+ f(x) = -(-5)^2 -10(-5) -20 = 5
Since the left and right side limits are equal, lim x-->-5 f(x) exists and equal to 5.
In order for x to be continuous at x=-5, f(x) must be equal to 5
Redefine f(-5) = 5
= (x-2)(2x+9)/(x-2)
= 2x+9
if x=2, 2x+9=13
define f(2)=13 to make it continuous
--------------------------------------…
lim x-->-5- f(x) = (-5)^2 +10(-5) + 30 = 5
lim x-->-5+ f(x) = -(-5)^2 -10(-5) -20 = 5
Since the left and right side limits are equal, lim x-->-5 f(x) exists and equal to 5.
In order for x to be continuous at x=-5, f(x) must be equal to 5
Redefine f(-5) = 5
-
f(x) has a removable discontinuity at x=2 implies that x-2 is a common factor of the rational function.
Try it!
No matter what the exercise says, f(2) does not exist!. the discontinuity removes the point (2, 13)
Try it!
No matter what the exercise says, f(2) does not exist!. the discontinuity removes the point (2, 13)