- Mon Oct 04, 2010 12:33 am
- Forum: Intermediate Algebra
- Topic: radius of circle is 1m > radius of another; find both radii
- Replies:
**1** - Views:
**976**

The eqn for the area of a circle is .

- Sun Oct 03, 2010 1:21 pm
- Forum: Advanced Algebra ("pre-calculus")
- Topic: need held dividing x^2-10x+50/x^4-15x^3+50x^2+250x-2500
- Replies:
**2** - Views:
**2097**

You cna learn how to do the factoring by going [url=hhttp://www.purplemath.com/modules/solvpoly2.htm]here[/url]

- Thu Jul 29, 2010 10:24 pm
- Forum: Advanced Algebra ("pre-calculus")
- Topic: techniques for finding an expression for geometric seqeunces
- Replies:
**1** - Views:
**1664**

They've got a lesson here: http://www.purplemath.com/modules/series3.htm

You can use the fomrulas. Like for 4,8,16,32,64, you have r=2, a=4. then a_{n}=a*2^{n-1}. And a=4=2^{2}, so a_{n}=(2^{2})(2^{n-1})=2^{2+n-1}=2^{n+1}.

You can use the fomrulas. Like for 4,8,16,32,64, you have r=2, a=4. then a

- Fri Apr 02, 2010 9:19 pm
- Forum: Trigonometry
- Topic: Solving trigonometry algebraically
- Replies:
**2** - Views:
**2683**

start w/ y=y then 3/tanx=2sinx so 3cosx/sinx=2sinx

3cosx=2sin^2x=2(1-cos^2x)

3cosx=2-2cos^2x

2cos^2x+3cosx-2=0

solve the quad eqn

3cosx=2sin^2x=2(1-cos^2x)

3cosx=2-2cos^2x

2cos^2x+3cosx-2=0

solve the quad eqn

- Tue Mar 09, 2010 7:39 pm
- Forum: Discrete Math
- Topic: probability point selected on segment is within 2 units of 8
- Replies:
**2** - Views:
**3066**

How did you get a distance of five units between 6 and 10?

What is the length of the whole line? What is the length that you want to hit? Divide the first by the second.

What is the length of the whole line? What is the length that you want to hit? Divide the first by the second.

- Wed Sep 09, 2009 7:22 pm
- Forum: Matrix (Linear) Algebra
- Topic: is there a 2x2 matrix A so A2 = -I?
- Replies:
**2** - Views:
**5141**

is there a 2x2 matrix A so A2 = -I?

(I is ident matrix)

(I is ident matrix)

- Tue Jul 28, 2009 4:46 pm
- Forum: Geometry
- Topic: find sruface area of sphere with cube inside with edge=1
- Replies:
**6** - Views:
**5831**

ill try that

thnx

thnx

- Fri Jul 24, 2009 4:21 pm
- Forum: Geometry
- Topic: find sruface area of sphere with cube inside with edge=1
- Replies:
**6** - Views:
**5831**

i guess i hadnt looked at it that way

that helps me picture it but still dont no how 2 find r??

tryed drawing it but cant get numbers??

that helps me picture it but still dont no how 2 find r??

tryed drawing it but cant get numbers??

- Mon Jul 20, 2009 4:12 pm
- Forum: Geometry
- Topic: find sruface area of sphere with cube inside with edge=1
- Replies:
**6** - Views:
**5831**

how do u use the cube to find the radius????

- Sun Jul 19, 2009 12:22 pm
- Forum: Geometry
- Topic: find sruface area of sphere with cube inside with edge=1
- Replies:
**6** - Views:
**5831**

problem- cube in a shpere edge of cube=1

i need to find teh surface area of the sphere??

i need to find teh surface area of the sphere??