Help College Algebra Factoring!

Main Question or Discussion Point

Y^6+124Y^3-125

the ^ means to the power of

help

Hurkyl
Staff Emeritus
Gold Member
One technique that is often useful in many problems is seeing if you can apply some sort of change of variable that makes a problem easier to solve, and then change back once you've solved the problem.

I tried the u^2=y^6 and u=y^3, but im still having issues

Remember, If r is a root of the equation F(x), then x-r is a factor.

(y^3 + 125) * (y^3 - 1)

you can factor y^3 +125.....anyone know how to do that?

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Fermat
Homework Helper
you could use your calculator to take the cube root of -125

y^3 + 125= (y + 5)(y^2 - 5y + 25)

If you want proof:

a^3 + b^3
a^3 + b^3 + 3a^2b + 3ab^2 - 3a^2b - 3ab^2
(a+b)^3 - 3a^2b - 3ab^2
(a+b)^3 - 3ab(a+b)
(a+b)((a+b)^2 - 3ab)
(a+b)(a^2 + b^2 - ab)

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when did this become college algerbra?

Math Is Hard
Staff Emeritus
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Tom McCurdy said:
when did this become college algerbra?
algerbra? :rofl: sorry -I had a teacher back in Alabama who pronounced it that way.

HallsofIvy
Homework Helper
I had a teacher in Boston who talked about "gammers" and "alphers".

matt grime
Homework Helper
Tom McCurdy said:
when did this become college algerbra?
my thoughts exactly

Math Is Hard
Staff Emeritus
Gold Member
HallsofIvy said:
I had a teacher in Boston who talked about "gammers" and "alphers".
:rofl: :rofl: :rofl:

Staff Emeritus
Gold Member
Dearly Missed
And then there was Alpher, Bethe, and Gamow.

I don't see what is so funny...

TD
Homework Helper
It's about how mathematicians should get at least 1 hour of Greek philology in their studies

What is the point if they understand the concepts and teach them to their students?

TD
Homework Helper
There is no 'point'. No-one is saying you're a worse teacher if you can't say 'alpha' correctly. It's just a thing some people appear to find funny...

matt grime
Homework Helper
I think in many parts of the UK the er and a endings have the same pronunciation anyway. Thus we spell the diminutive of fellow as fella or feller depending on your preference. And Pitta (as inj bread) is the same as pitter (one who pits, as in to pit your wits against seomthing). Or summa (summa cum laude) and summer. I would suggest that this holds true in the Boston area too. I remember being there once and being told by some american friends that I would enjoy the accent when some bloke shouted out at soem traffic lights, "use your blinker pal" (indicator) and them taking great delight in repeating it as "blink-AH"

HallsofIvy
Homework Helper
We appear to have completely lost any mathematical content in this thread!

However, when I was in college, a delivery area behind the cafeteria had been clearly lettered "No Pahking"!

...and this was in Boston?

HallsofIvy