HOMEWORK HELP THREAD! - Page 10

Nostalgia · August 14th, 2009, 01:04 AM

Would someone be able to describe a couple anatomical and physiological comparisons between plants using C4 photosynthesis, and those using CAM photosynthesis?

Edit: I've basically got the physiological differences between the two covered, as well as an analysis on kranz anatomy for C4 plants, and I also understand that CAM plants may be other types of C4 plants, but I need an anatomical difference between the two. So, anyone have an answer?

quitejaded · October 13th, 2009, 02:04 AM

I just read Karl Marx's Estranged Labour. Anyone understand Marx's views of value of labour and humanity?

493pokemon1 · October 18th, 2009, 07:16 PM

Im supposed to do this for next thursday

So any idea on how?

Plz

Takuya · October 20th, 2009, 01:00 AM

Here's a math problem I'm having trouble with:

Pizzas are to be ordered for a party. The restaurant offers three specials.

Special A: a small, together with a medium pizza, for 13 dollars.
Special B: 2 medium pizzas for 14 dollars.
Special C: a large pizza for 15 dollars.

A small pizza has diameter 12", a medium pizza 16" and a large pizza 20".

Rank A, B and C from the greatest to the least square inches per dollar.

CBA, BCA, ABC, ACB, BAC

So yeah. Problem from a math competition in 1997 for a scholarship to UMBC/UMCP. We're supposed to be able to solve problems like this in less than 3 minutes. <<

Marly · October 20th, 2009, 01:08 AM

Er. Correct me if I'm wrong on this. But:

Special A: 12+16=28 28/13= $2.15 per square inch

Special B: 16(2)= 32 32/14= $2.29 per square inch

Special C: 20/15= $1.33 per square inch

I'm pretty sure that's right

Takuya · October 20th, 2009, 01:11 AM

That is correct (I think)! :D I really need to practice my basic math logic more. I was think too much into it, adding the areas using their diameters <.<;

EDIT: or rather, (pi)r^2, etc.
EDIT 2: Not really sure whether diameters can be figured in for square inches, but... idk.

stephaknee · October 20th, 2009, 01:15 AM

The answer may have been right, but Marly wrongly used the diameter as the the sq in. You have to find the area with the diameters given.

Takuya · October 20th, 2009, 01:18 AM

Edited that into my previous post. Instead of adding together the diameters, it should be sq. inches.

EDIT: Second note; for this question, competitors weren't allowed calculators.

stephaknee · October 20th, 2009, 01:19 AM

To answer your second edit.

A = PR^2
R = D/2.

Takuya · October 20th, 2009, 01:38 AM

After a couple of minutes with notepad and calculator, I got

A: ((pi)6^2 + (pi)8^2)/13 = 24.166
B: 2((pi)8^2)/14 = 16.157
C: (pi)10^2/15 = 20.944

So it should be ranked - BCA

<_< Now to do this without a calculator.

stephaknee · October 20th, 2009, 02:02 AM

Quote:

Originally Posted by Takuya

After a couple of minutes with notepad and calculator, I got

A: ((pi)6^2 + (pi)8^2)/13 = 24.166
B: 2((pi)8^2)/14 = 16.157
C: (pi)10^2/15 = 20.944

So it should be ranked - BCA

<_< Now to do this without a calculator.

Leave in terms of pi

A: 36pi + 64 pi = 100/13 pi = 7 + 9/13 pi.
B: 64 pi + 64 pi = 128 pi / 14 = 9 + 1/7 pi
C: 100/15 = 6 2/3 pi

So its BAC. Like I said early, marly got the right answer, but didn't do it in the way the question asked.

Takuya · October 21st, 2009, 12:29 AM

Quote:

Originally Posted by stephaknee

Leave in terms of pi

A: 36pi + 64 pi = 100/13 pi = 7 + 9/13 pi.
B: 64 pi + 64 pi = 128 pi / 14 = 9 + 1/7 pi
C: 100/15 = 6 2/3 pi

So its BAC. Like I said early, marly got the right answer, but didn't do it in the way the question asked.

*CAB

Ranked from least to greatest. But that's right.

Now, a simple question: How does

_1_
√2

equal 2^(-1/2)?

Eternal Redemption · October 21st, 2009, 12:41 AM

Quote:

Originally Posted by Takuya

*CAB

Ranked from least to greatest. But that's right.

Now, a simple question: How does

_1_
√2

equal 2^(-1/2)?

x^1/2=Square root of x. So 2^1/2 = square root of 2. Negative powers are reciprocals. So you flip it upside down and get :
_1_
√2

:D

~~gramp anime scholar~~ · October 21st, 2009, 12:43 AM

Quote:

Originally Posted by Takuya

*CAB

Ranked from least to greatest. But that's right.

Now, a simple question: How does

_1_
√2

equal 2^(-1/2)?

Another way to write the square root of a number, say x, is x^(1/2).

Now, when you have a fraction where it's 1/x, you can depict x in terms of exponents. 1/x is equivalent to x^(-1)

So if you have 1/√x, then you have 1/x^(1/2) but you also know that 1/x is x^(-1), so then 1/x^(1/2) is equivalent to x^(-1/2)

In this question, x would have a value of 2.

Eternal Redemption · October 21st, 2009, 12:45 AM

Quote:

Originally Posted by gramp anime scholar

Another way to write the square root of a number, say x, is x^(1/2).

Now, when you have a fraction where it's 1/x, you can depict x in terms of exponents. 1/x is equivalent to x^(-1)

So if you have 1/√x, then you have 1/x^(1/2) but you also know that 1/x is x^(-1), so then 1/x^(1/2) is equivalent to x^(-1/2)

In this question, x would have a value of 2.

Agreed. Refine what I said into this. :/