Continuity

Calculus Level 1

Let f ( x ) = { x 2 x 2 x 2 if x 2 a if x = 2. f(x) = \left\{ \begin{array}{ll} \frac{x^2-x-2}{x-2} & \mbox{if } x \neq 2 \\ a & \mbox{if } x = 2. \end{array} \right. If f ( x ) f(x) is continuous for all real values of x , x, what is a ? a?


The answer is 3.

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

2 solutions

Seth Lovelace
Jun 24, 2014

So to begin our argument, f(x) = x 2 x 2 x 2 \frac{x^{2}-x-2}{x-2} . This function is

defined for all values x except 2, as that causes the denominator of

the argument to be zero. To find "a", you can take the limit of the

function.

l i m x = > 2 x 2 x 2 x 2 lim_{x=>2} \frac{x^{2}-x-2}{x-2}

This function can be factored in the numerator to be:

l i m x = > 2 x 2 x 2 x 2 lim_{x=>2} \frac{x^{2}-x-2}{x-2}

l i m x = > 2 ( x + 1 ) × ( x 2 ) x 2 lim_{x=>2} \frac{(x+1)\times (x-2)}{x-2}

l i m x = > 2 x + 1 lim_{x=>2} x+1

At this point, the two may be substituted for x

x+1 = a

2+1 = 3 \boxed {3}

Sorry about the arrows by the limit, could not figure out how to do them.

Seth Lovelace - 6 years, 11 months ago

Log in to reply

Its okk as your Solution is correct....

Ashwani Shukla - 6 years, 10 months ago

Hello,

as for f(x) = (x+1)(x-2) / (x-2) = x+1 , as x not = 2,

since it is continous for all values of x,

f(x) = x + 1 for x=2,

a = f(2) = 2 + 1 =3....

thanks.....

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...