Oh but. No parentheses around x squared so I have to factor whole thing


So its like( x^2 +x -12)

So need to break into x times something and x time something that produces to -12


So (x-3)(x+4) or (x-4)(x+3) both work


But I'm confused where the middle x went from the original problem. X^2 lends the2 x 's but what about the middle x before the -12? Also does it have to produce -12 aand add to 1 since a is 1? In which case only -3 and 4 would be valid

Ty everyone

watch those 2 videos azrad posted, they're honestly for your benefit
those videos will put it on a very understandable level

yes, you got it right, it has to be (x-3)(x+4) because +4 and -3 add up to +1
just be patient and take it slowly until you have digested the key steps

the principle is (x+c)(x+d)=x^2+[c+d]x+cd
so here the issue was find c and d so that
c+d=1 and c*d=-12

and to



everything is easy once it is understood
but for some it takes a little bit time and work to understand it

postscript:

hating math does not help, if you think negatively you make it more difficult for yourself
you will need some sort of math for most professions, there must be a reason you are taking this class
take it as a challenge and you will get there

btw, there was a time i hated english but i got over it

This post was edited by brmv on Jan 22 2014 01:46am

Thanks. Also on that -3 4 answer it is under 2

2/ -3, 4


So would the answer be -1.5 and 2? X is everything but -1.5, 2?



Also i got for this one:

5) x^2-2x-15

(x+3)(x-5)

But the book is telling me answer is (-infin, +infinite)

This post was edited by fingerling on Jan 22 2014 01:48am

calculate g(-1.5) , g(2) , g(-3), g(4) and tell me which are defined.



Do you disagree? find me an x which is not in the domain, eg cannot be calculated.

This post was edited by carteblanche on Jan 22 2014 01:51am

no, since the solution is (x+4)(x-3) it is +4 and -3 because then the multiplication of (x+4) with (x-3) becomes zero

for your problem 5, you got the right factoring of x^2-2x-15=(x-3)(x+5)
so what was the question for that problem precisely?



not sure what you mean with g(-1.5) and g(2)
but for problem 5 the question is not to find the x's when the function becomes zero
yes, you can calculate the function for all values except when you go to plus or minus infinity

it is always essential to fully understand the question and not assume that the same approach is needed as for the previous one

This post was edited by brmv on Jan 22 2014 01:55am

It just says find the domain:

F(x)= x^2 -2x -15

If I get x-3 and x+5 I thought that meant any value is possible for x except -3 and +5?? But its says any value to infinity both ways is valid ?


I'm required to take this for biochemistry... My phd professor who teaches organic and biochemistry coursss told me you don't even really need much math for it.

I might have to take physics and calc 2. So idk this may not be the field for me

denominator =/= 0
the numerator can be 0

you already have a degree?

he thinks -1.5 and 2 are not in the domain of g. so i want him to calculate g(-1.5) and g(2). if it's possible to get a number, then clearly it is in the domain.