1. ## help!! polynomial

heres a question i dunt get how to solve, the width of a square based storage 3m less than its height. THe tank has a capacity of 20m^3. If the deimension are integer value in metres, what are they?

2. width of a square based storage 3m less than its height. THe tank has a capacity of 20m^3.
$\displaystyle w = h-3$

area of base, $\displaystyle B = (h-3)^2$

$\displaystyle V = Bh = h(h-3)^2 = 20$

$\displaystyle h^3 - 6h^2 + 9h - 20 = 0$

rational root theorem ... possible positive integer roots {1, 2, 4, 5, 10, 20}

go for it.

3. Originally Posted by lickman
heres a question i dunt get how to solve, the width of a square based storage 3m less than its height. THe tank has a capacity of 20m^3. If the deimension are integer value in metres, what are they?
$\displaystyle V = h(h-3)^2$. But $\displaystyle V = 20$. Therefore $\displaystyle 20 = h(h-3)^2$. Solve for h.

Trial and error is an efficient way of getting h and therefore getting the dimensions of the tank.

4. Originally Posted by lickman
heres a question i dunt get how to solve, the width of a square based storage 3m less than its height. THe tank has a capacity of 20m^3. If the deimension are integer value in metres, what are they?

So the volume of this container is W*W*H. We know that W=H-3, so let's plug that in. The volume is 20m^3, so (H-3)(H-3)H=20.

Can you solve it from here?

EDIT: I am WAY late.

5. volume is W*W*H? why is W*W? isnt W x L x H lol i'm seriously retarded so plz forgive me/

6. Originally Posted by lickman
volume is W*W*H? why is W*W? isnt W x L x H lol i'm seriously retarded so plz forgive me/
The base is a square , is it not?

7. lmfao thanks , but i seriously dunt know these anymore, base always b^2[/tex]? anyway i need some knowledge in geometry or shape calculating before solving these. lol

8. is there anyway for a easier to analysis problem solving question with factors etc

9. Originally Posted by lickman
is there anyway for a easier to analysis problem solving question with factors etc
I don't understand this sentence. Can you please explain?

10. is there anyway for a easier to analysis problem solving question with factors etc
lol sorry for my jibberish english
is there anyway to make it easier to analysis problem solving questions with factors? by certain words they use etc..

11. Originally Posted by lickman
is there anyway for a easier to analysis problem solving question with factors etc
lol sorry for my jibberish english
is there anyway to make it easier to analysis problem solving questions with factors? by certain words they use etc..
Hmm, good question. I don't know if I can answer that in general, but I'll tell you the key words for this problem.

"square base" - this means that the length and width are equal.
"width... 3m less than its height" - this is great because we can now relate the width to the height.
"capacity of 20m^3" - we got the volume of the container now.

Now I think how do I put this together and use it. Well the volume of a box is the L*W*H, length times width times height. We know this equals 20. So the length and width of the base are the same as we said before, so we can say W*W*H=20. Now the width is 3 meters less than the height. Write that out just like it sounds. W = H-3. Now you can substitute this in and you got your answer.

I don't know if that helps at all, but my advice is look for all the key info given. Write down the numbers given and what they pertain to. The hardest part usually will be making some kind of substitution, so look for some kind of relation that you can use to make a substitution.