Friday

August 29, 2014

August 29, 2014

Posted by **Alissa** on Monday, September 21, 2009 at 9:21pm.

- Algebra -
**Shavaleir**, Monday, September 21, 2009 at 9:27pm(-2-2)=0 (-2+2)= -4

(2-2)=0 (2+2)= 4 so they are not the same because the first one is a negative 4 and the second is a positive 4

- Algebra -
**Reiny**, Monday, September 21, 2009 at 10:01pmx(x+2)(x+2)/(x-2)(x+2) line 1

= x(x+2)/(x-2) line 2

you are dealing with explicit vs implicit restrictions.

Some authors of textbooks will list as restrictions all values which make any of the denominators zero.

Other authors, and yours is one of them, will restrict only those factors which were divided out

let me explain:

let x=2

line 1 = 32/0 which is undefined

line 2 = 8/0 which is undefined

so technically line 1 is still equal to line 2 when x=2 and no need to restrict it as (x cannot be equal to 2)

let x=-2

line 1 = 0/0 which is indeterminate (wait till you take Calculus for that one)

line 2 = 0/-4 = 0 a real number

so clearly line 1 is no longer equal to line 2, making x = -2 a "necessary" restriction.

It is a fine distinction. I used to accept both types of answers.

**Related Questions**

Algebra - Hello again, I am now working on trying to find the relation of x = 1...

college algebra - 1.for the given function f&g, find the following and state the...

College Algebra - For the given functions f and g, find the following and state ...

Algebra - Given the following function rules and domains, find the associated ...

Algebra - 13. Find the domain of y=2x+1 Bobpursley said: The domain of x is not ...

algebra - if f(x)=lnx, g(x)=e^3x, and h(x)=x^4 find following A)(f of g)(x)and ...

college algebra - For the given functions f and g find the following and state ...

Pre-Calc - Suppose that f has a domain of A and g has a domain of B. (a). What ...

College Algebra - I need to find the domain of f, the excluded values of f, the ...

Small Group Communication - Regulating participation, climate making, and ...