help!

[humakhan]

Find the coordinates of the center and the measures of a radius for the circle whose equation is : (x - 8)^2 + (y + 4)^2 = 121

help ?
please

 

[tkhunny]

Once again, you have presented a trivial problem statement and managed to show no work whatsoever.

The answers are staring you in the face. Look up just one thing on equations of circles and you will be done with this one.

This problem statement is intended to test your knowledge of the FORM of the equation of a Circle. Read up on the form and tell us what you get.

 

[humakhan]

ok i'll check in my book once again

 

[humakhan]

this way :
right

(x - h)^2 + (y - k)^2 = r^2

[( x - (-8)]^2 + [(y - (-4)]^2 = 121^2
h = -8
k = -4
r = 121
the center of the circle is at (-8,-4)
radius is 121....so diameter is 14641

correct

 

[pka]

Somewhat CORRECT.
BUT: r=11 & d=22.

 

[humakhan]

oh but can i ask how is
r = 11 and d = 22 ????

 

[Guest]

the diameter of a circle is 2 times the size of the radius so if your radius is
121 then the diameter would twice that would it not?? Im probably way off but that just popped into my head when i read it :lol:

I hope that i didn't mess you up even more... by the way... i worked out the problem as well and i came to the same answer (14641)

~Ainsley~

 

[humakhan]

yeah ur right
twice as much
yeah that is the answer i am sure of it

 

[pka]

your radius is 121

NO THAT IS NOT CORRECT!

See that r<SUP>2</SUP>=121 or r=11 and d=22.

 

[pka]

i hope you understand it now...math is confusing but once you get the hang of it, it's kind of fun.

Anlsley, I do hope that you will get the hang of it.
Please be sure you understand the problem yourself before posting.

 

[humakhan]

and sometimes fun.. but mostly confusing mannnnnnnn

please i get the answer i got....
i really dont know how u got r as 11 and d as 22
please do explain....PLZ

 

[humakhan]

OH MY GOD I GET IT
mannnnnnnnnnnn .

u did 11 * 11 to get the answer of 121.....
then u 11 * 2 and got 22 as ur d
ok tahnks so much

 

[Denis]

then u 11 * 2 and got 22 as ur d

HUMA!!! ....22 as YOUR DIAMETER :evil:

 

[happy]

Good luck with Geometry, Huma. I know you can do it!

 

[humakhan]

thats wht i said
d = 22
i get it now denis relax ok.....

ohh thanks happy = )

 

[tkhunny]

We spent so much time on the diameter, no one noticed the center wasn't correct?

 

[humakhan]

-8. -4
isnt correct...?
if its not then how can i get the correct answer
i think i used the right way to find the solution right?

 

[tkhunny]

-8. -4
isnt correct...?
if its not then how can i get the correct answer
i think i used the right way to find the solution right?

Look very carefully at these parts:

x-h

y-k

Note the subtraction. What does your ORIGINAL equation show?