Monday

December 22, 2014

December 22, 2014

Posted by **Angela** on Sunday, July 24, 2011 at 8:20pm.

a) f(x)=x^20

b) g(x)=1/(x-3)

c) h(x)=1/(4x^2=21x-18)

d) k(x)=sqrt (4x^2-21x-18)

e) p(x)=1/sqrt(4x^2-21x-18)

- Pre Cal -
**Reiny**, Sunday, July 24, 2011 at 9:18pma) -- anything goes

b) -- anything except x=3

c) we need factors of

4x^2 - 21x - 18

= (x - 6)(4x + 3)

so x ≠6 or x ≠ -3/4

d) Now the number inside the √ cannot be negative.

so x ≤ -3/4 or x ≥ 6

e) not the number inside cannot be zero or negative.

you do that one, let me know what you got.

- Pre Cal -
**Angela**, Sunday, July 24, 2011 at 9:23pmisn't it the same as d, because the domain is looked at in the demoninatior?

- Pre Cal -
**Reiny**, Sunday, July 24, 2011 at 9:30pmno,

in d) the √ was a numerator while in e) it is now a denominator.

So now we also have to worry about division by zero.

btw, I just noticed a typo which probably caused confusion.

e) should have said:

" e) note that the number inside cannot be zero or negative. "

Of course the result is zero when x=6 or x=-3/4, which we cannot have

so just make it : x < 3/4 OR x> 6

- Pre Cal -
**Angela**, Sunday, July 24, 2011 at 9:32pmand x<3/4 or x>6 is the answer?

- Pre Cal -
**Reiny**, Sunday, July 24, 2011 at 9:42pmIf you understood what I worked for you, you should have realized that I missed the negative sign in x<-3/4 as a typo.

so .......

**x < -3/4 OR x > 6**

- Pre Cal -
**Angela**, Sunday, July 24, 2011 at 9:44pmOops. sorry i was distracted while writing and forgot to put the negitive.

- Pre Cal -
**Dalidah**, Tuesday, August 16, 2011 at 4:54pmthis is wrong

**Answer this Question**

**Related Questions**

Pre Cal/ domain - Domain of a) x^20 b) 1/(x-3) c)1/(4x^2-21x-18) d) sqrt(4x^2-...

Algerbra - how do you solve 7(3x+4)=8(2x+5)+13 expand the parenthesis...I will ...

inequality expresion - The cost of a long distant telephone call is $0.36 for ...

Algebra - Is this right? 7(3x-2)=70 21x-14=70; 21x-14+14=70+14; 21x=84; x=4

Algebra - Is this right? 7(3x-2)=70 21x-14=70; 21x-14+14=70+14; 21x=84; x=4

algerbra - 7(3x+4)=8(2x+5)+13 how would I start a equation like this would it be...

Math - Simplify I came up with 5.5 (15x^5-21x^4+21x^2)/(3x^2 ) not sure if I did...

algebra - factor the following equation: 6x^2 - 21x - 9 i've tried to factor it ...

math - *simplify by combining like terms, if possible. then, remove the GCF and ...

MATH - This problem makes no sence to me i tried it but i know i am completely ...