Mathematics - 5 August 2007

If two circles are externally tangent, how many common tangents do they have?

2007-08-05 16:29:11 · 3 answers · asked by ½ÃÂù ± 2

I really need one. People in my high school suggested the Ti-89 but its like 200 bucks...lol any ideas?

2007-08-05 16:28:55 · 8 answers · asked by tennisman2156 2

2007-08-05 16:17:55 · 5 answers · asked by Anonymous

Even using the formula I can't even get the right anwser this is none sense.
-b+/-√b²-4ac /2a

Prob.
-x²-8x+3=0

Solving.
x²+8x-3=0
-8+/-√64-4*1*-3/2

x=-8+/-√76/2

The anwser is totally wrong, how useless the formula is...

Complete the square.

(x+8/2)²-64/4=-3 +64/4
(x+8/2)²=52/4
(x+8/2)=2+/-√13/2
X=-8+/-√13/2

2007-08-05 16:15:52 · 4 answers · asked by Anonymous

1/2 div 3 1/4

2007-08-05 16:13:41 · 3 answers · asked by Jamie 1

2007-08-05 16:12:31 · 5 answers · asked by Anonymous

what do
!
∑
┴
and
(a,b)
mean? sorry its just back to school and hard to remember

2007-08-05 16:11:16 · 7 answers · asked by Tasha 3

We know the answer just not the steps

2007-08-05 16:01:45 · 9 answers · asked by jess b 1

2007-08-05 15:57:54 · 4 answers · asked by Anonymous

2007-08-05 15:57:15 · 4 answers · asked by Anonymous

I'm trying to determine an expression for average torque during the power stroke from a one-cylinder engine with a standard crankshaft.

Let the crankshaft angle when the piston is all the way down be 0 degrees, and when the piston is all the way up, let it be 180. Let the connecting rod be long so the angle between it and vertical can be ignored.

An expression for the instantaneous torque at 90 degrees (when the piston is halfway from bottom to top) would be
T = F*d
where F is the force and d is the distance from the crankshaft centerline to the bearing where the connecting rod and crankshaft mate (the lever arm).

The expression
T = F*d*sin(theta)
should be valid while theta varies from 0 to 180, the 1/2 revolution during which power is available. )Probably F would not be a constant but let's assume it is.)

My problem is how to get the average torque over the 180 degrees of the power stroke. Please, I really need to learn how, more than I need the answer.

Thanks

2007-08-05 15:49:17 · 2 answers · asked by sojsail 7

2007-08-05 15:49:13 · 4 answers · asked by mastermind 1

√x+7 + 5 = x

a) {9}
b) {2,9}
c) {9,18}
d) {2}

2007-08-05 15:39:18 · 6 answers · asked by Robby 2

2007-08-05 15:37:54 · 6 answers · asked by shawn 1

2007-08-05 15:32:38 · 1 answers · asked by Anonymous

It says to "write each division expression as a multiplication expression to find the quotient" 1/2 divded by 4/5 how the heck u do that

2007-08-05 15:30:27 · 11 answers · asked by Jamie 1

Five natural numbers D1,D2,D3,D4 and D5 ar such that their sum is odd. If the product of D3,D2 and D1 is odd and (D2D3+D3D4+D4D5) is not even , which of the following is true ?


(1)D4 is even , only if D5 is even

(2)D4 is always even

(3)D4 is always odd

(4)D4 is odd ,only if D5 is odd.


After some fight , i chose 1,3,5,7,11 which satisfies the conditions.

but while trying to choose the answer , i got stumbled because question has "if","always","only if" ....so not able to choose the answer.

How to solve this kind of problem ?

2007-08-05 15:27:20 · 1 answers · asked by calculus 1

#1. Multiply (6t - 5)(6t + 5)

#2. Multiply and Simplify (3n)^6 * (3n)^7


Need answers to check my own work. Thanks

2007-08-05 15:25:57 · 5 answers · asked by Anonymous

Points Q, R, and S are on a line segment so that R is between Q and S. If QR = 4RS, what percent of QS is QR?

There are 28 students in a math class and 23 students in a chemistry class. If eight of these students take both math and chemistry, what is the ratio of the number of students taking only chemistry to taking only math?

2007-08-05 15:24:23 · 4 answers · asked by ? 2

2007-08-05 15:20:47 · 5 answers · asked by Anonymous

Even using the formula I can't even get the right anwser this is none sense.
-b+/-√b²-4ac /2a

Prob.
-x²-8x+3=0

Solving.
x²+8x-3=0
-8+/-√64-4*1*-3/2

x=-8+/-√76/2

The anwser is totally wrong, how useless the formula is...

Complete the square.

(x+8/2)²-64/4=-3 +64/4
(x+8/2)²=52/4
(x+8/2)=2+/-√13/2
X=-8+/-√13/2

2007-08-05 15:14:12 · 6 answers · asked by Anonymous

2007-08-05 15:12:55 · 8 answers · asked by Anonymous

Please... I really need to know what the | means and how to solve?

2007-08-05 15:09:17 · 9 answers · asked by xrandomnessx 2

Solve the system by addition.
5x – 4y = –5
x – 2y = –7

2007-08-05 15:05:53 · 8 answers · asked by sittinncat 1

please answer this with workings out please
Two circular discs are touching. The diameter of the larger disc is seven times that of the smaller disc, and the distance between their centres is 28cm.
What is the diameter of the smaller disc?
thanks to anyone smart enough to work this out lol ; )

2007-08-05 15:05:08 · 3 answers · asked by Anonymous

A number is called "wise" if it has exactly 5 positive integer factors. What percent of the first 20 positive integers are "wise"


James took 2/5 of the wrapped taffy from a large candy box. Bill removed 2/3 of the remaining taffy. If Bill removed 26 pieces of taffy from the box, how many pieces of taffy were in the box before James took any?

2007-08-05 15:04:46 · 5 answers · asked by Anonymous

Describe the graph. Indicate whether the line would be a solid or a dotted line. Indicate which quadrant would be shaded
x + y = 4
–x + y = 2

2007-08-05 15:02:38 · 2 answers · asked by sittinncat 1

Formula:
-b +/- √b²-4ac / 2a

prob.
x²+6x-4=0
plug values.

1) -6 +/- √36-4*1*-4
2) -6 +/- √52

I retry. Complete Square way.

(x+6/4)²-36/16=4 +36/16
(x+3/2)²=100
\ect...Which will turn out different. BS.

God SMACK this is G@y.
Damn. Help, Quadratic are so stupid shyt. Can't even solve this. Damn.itt

2007-08-05 14:52:46 · 6 answers · asked by Anonymous

5x-1 3x +9 y+8 Y3-6

2007-08-05 14:50:10 · 2 answers · asked by Anonymous

g (x) = 3x^2 + 5x-3

state the domain

thank you

2007-08-05 14:45:16 · 3 answers · asked by peanut1 1