Math 11 (Principles) Final Exam Question (tricky, to me atleast)

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June 16th 2008, 04:51 PM
MarkMcl07

[Solved] Math 11 Final Exam Question

http://img207.imageshack.us/img207/6...ecirclemy5.jpg

Hello, im new to the forum and i have a question.

this exact question was the only thing i was truly stumped on my final exam today, according to the equation the sector angle is larger than 360 degrees, but a circle can only have 360 degrees right?

does that mean that the sector goes around the circle more than one time?

i spent around 30 minutes retrying this question over and over untill i finally gave up and used the answer that i saw was most correct given the circumstances

How would YOU the "Mathhelpforum" User solve this crazy geometry problem?
June 16th 2008, 06:31 PM
MarkMcl07

yes or no

i do understand that this question, may or may not be, too large or too little of a challenge for some people, but if anyone DOES know and just is too lazy too type out a big answer/post like i have done with the question, all i realy need is this:

Did i do it right? YES or NO
Is that answer correct? YES or NO
Does that question deserve to be on a Grade 11 Final Exam? YES or NO

thanks again
June 16th 2008, 09:16 PM
earboth

Quote:

Originally Posted by MarkMcl07

http://img207.imageshack.us/img207/6...ecirclemy5.jpg

Hello, im new to the forum and i have a question.

this exact question was the only thing i was truly stumped on my final exam today, according to the equation the sector angle is larger than 360 degrees, but a circle can only have 360 degrees right?

does that mean that the sector goes around the circle more than one time?

i spent around 30 minutes retrying this question over and over untill i finally gave up and used the answer that i saw was most correct given the circumstances

How would YOU the "Mathhelpforum" User solve this crazy geometry problem?

You used the term of the circumference insted of the area:

$a_{sector} = \pi \cdot r^2 \cdot \frac x{360}$

$416 = \pi \cdot 225 \cdot \frac x{360}$ will yiel

$x \approx 105.9^\circ$
June 16th 2008, 09:31 PM
MarkMcl07

Quote:

Originally Posted by earboth

You used the term of the circumference instead of the area:

$a_{sector} = \pi \cdot r^2 \cdot \frac x{360}$

$416 = \pi \cdot 225 \cdot \frac x{360}$ will yiel

$x \approx 105.9^\circ$

dang, i had 2 other finals that day and by the time i was on this question in math i was stressed and tired and i was being rushed, it seems i read the formula i was given:
$a_ = \pi \cdot r^2 \cdot \frac x{360}$
and saw the A and assumed it stood for Area ( DARN YOU "Arclength" and your given variable being similar to "Area" )

thankyou very much for the help, sucks that i got it wrong, perhaps even got a couple others but i dont remember them
June 16th 2008, 09:38 PM
Mathstud28

Quote:

Originally Posted by MarkMcl07

http://img207.imageshack.us/img207/6...ecirclemy5.jpg

Hello, im new to the forum and i have a question.

this exact question was the only thing i was truly stumped on my final exam today, according to the equation the sector angle is larger than 360 degrees, but a circle can only have 360 degrees right?

does that mean that the sector goes around the circle more than one time?

i spent around 30 minutes retrying this question over and over untill i finally gave up and used the answer that i saw was most correct given the circumstances

How would YOU the "Mathhelpforum" User solve this crazy geometry problem?

I think this is an appropriately difficult question for an eleventh grader. You don't?
June 16th 2008, 09:41 PM
MarkMcl07

Quote:

Originally Posted by Mathstud28

I think this is an appropriately difficult question for an eleventh grader. You don't?

i didn't at the time, considering i had my formulas mixed up, seeing a circle thats "impossible" matched with a diagram that shows otherwise, i didnt think of it as fair.

Edit:
infact, i feel like an idiot, i did it correct the first time, wrote down 211 degrees (the answer) but then i freaked out and read the formula wrong and corrected myself.. with the wrong answer, maybe the teacher will see the scratched out 211 and laugh, half marks? perhaps. id hope so, but i did make a mistake and if i get 0 for the question it doesn't really matter to me.
June 16th 2008, 09:43 PM
Mathstud28

Quote:

Originally Posted by MarkMcl07

i didn't at the time, considering i had my formulas mixed up, seeing a circle thats "impossible" matched with a diagram that shows otherwise, i didnt think of it as fair.

Haha, don't worry, we all do it now and again. But just think you still have trig to look forward to, and then calc, and then enumerative combinatorics, and then representation theory, and then...I digress

:cool:
June 16th 2008, 09:45 PM
MarkMcl07

Quote:

Originally Posted by Mathstud28

Haha, don't worry, we all do it now and again. But just think you still have trig to look forward to, and then calc, and then enumerative combinatorics, and then representation theory, and then...I digress

:cool:

heh. Part 2 of my exam is tommorow, Co-Ordinate Geometry, exciting eh?
June 16th 2008, 09:47 PM
Mathstud28

Quote:

Originally Posted by MarkMcl07

heh. Part 2 of my exam is tommorow, Co-Ordinate Geometry, exciting eh?

$D=\sqrt{(x-x_0)^2+(y-y_0)^2}$

Yes...very much so...it is totally fun.........(Fubar)