# Posts by Qun

Total # Posts: 21

**MATH**

Yes, it is right.

*September 30, 2008*

**maths**

You need to isolate P from the rest. Basically you do opposite operations to isolate a variable. In this case, subtract 5/3 on both sides: then P = q - 5/3

*June 20, 2008*

**Algebra II**

Here is the answer: Let S represent the sum of the expression then: S = 1/5 + 1/5^2 +... + 1/5^n ---- (a) multiply both sides by 1/5 (1/5)S = 1/5^2 + 1/5^3 +.. + 1/5^n + 1/5^(n+1) ---- (b) use equation (a) subtract equation (b) (4/5)S = 1/5 - 1/5^(n+1) multiply 5 on both sides...

*April 5, 2008*

**Calculus: drwls, please**

Hi, You need to draw f(x) =1/x first and then transform it to f(x) = (1/x) - 4 To draw f(x) = 1/x, all you need to do is find several points, example: let x=1, then f(1)=1, you get one point (1,1) let x = 0.5, f(0.5)=1/0.5=2, another point (0.5,2). Try to get 5-10 points and ...

*April 4, 2008*

**Advanced Math**

Yes it is suppose to be f(n) = n^2 + 4n is O(n^2) : Hi, I assume n>1. let g(n)=n^2 This is straight forward according to big O notation. f(n) = n^2 + 4n <= n^2 + 4n^2 = 5n^2 That means |f(n)|<=C|g(n)| where C is a constant. According to big O definition f(n) is O(n^2)

*April 2, 2008*

**Math**

a math expression has meaning in it, it is not just a bunch of operations. The older of operations is a set of rule that everybody will follow so that we have a solid foundation to communicate with each other so that the meaning in an expression can be delivered without ...

*March 31, 2008*

**MATH**

Linear model mean the rate of change is constant. SO the rate is (4.4-24.3)/45 = 0.442 a) So the model function is f(t)=24.3 -0.442t b)in year 1975, t=30 f(30)=24.3-0.442*30 = 11.04 about 11 million. c) in year 1980, t=35 f(35)=24.3-0.442*35 = 8.83 million

*March 31, 2008*

**geometry**

hint: how are diameter and circumference related? How are radius and diameter related?

*March 24, 2008*

**math**

x^2-10x+25

*March 24, 2008*

**math 116**

This is the reason, using 1/2 + 1/3 as example: the denominator means the number of equal parts you divide the whole thing into. 1/2 means you divide the whole thing into 2 equal parts and you take one part. 1/3 means you divide the same whole thing into 3 equal parts and you ...

*March 24, 2008*

**math**

The standard notation for the length of medians: a=(1/2)*sqrt(2C^2+2B^2-A^2) b=(1/2)*sqrt(2C^2+2A^2-B^2) c=(1/2)*sqrt(2A^2+2B^2-C^2) square both sides: a^2=(1/4)*(2C^2+2B^2-A^2) b^2=(1/4)*(2C^2+2A^2-B^2) c^2=(1/4)*(2A^2+2B^2-C^2) multiply 4 on both sides: 4a^2=(2C^2+2B^2-A^2) ...

*March 23, 2008*

**math**

this line goes through origin. So the y-intercept is 0

*March 23, 2008*

**math**

Find the distance formula in the textbook and plug in numbers.

*March 23, 2008*

**Math(Easy Survey Please Help)**

1. Do you exercise or work out on a regular basis? no 2. Are you male or female? male 3. Do you smoke? no 4. How many carbonated soft drinks do you consume in a week. none 5. Do you drink coffee. occasionally 6. How many servings of fruit, or fruit juice do you consume in a ...

*March 22, 2008*

**Math**

Your problem is a wrong one. tenth is the first decimal digit.

*March 22, 2008*

**Math**

This is rather about the concept: 1) Identity means both sides are equal no matter what the value x will take. example: 2+x=x+2 2) inconsistent: means the equation is not true regardless the x value. example: 2+x=3+x 3) conditional: The equation is true at certain x value. ...

*March 21, 2008*

**math**

1) divide both sides by 25, we get x^2=13/25 take square root x = +/- sqrt(13/25) sqrt means square root. example: sqrt(5) means square root of 5. 2) The same kind of problem: divide by 2 on both sides: (x-5)^2 = 3/2 take square root: x-5 = +/- sqrt(3/2) add 5 on both sides: ...

*March 21, 2008*

**Algebra**

Let Total be x 1) Pink (1/2)x remain (1/2)x 2) pink (3/4)*(1/2)x remain (1/4)(1/2)*x 3) Orange (1/2)(1/4)(1/2)x remain: (1/2)(1/4)(1/2)x So the red is (1/2)(1/4)(1/2)x Which is one-16th of the whole thing, which is 16.7% Contact me for quick homework help.

*March 18, 2008*

**Trigonometry**

replace 150(in the parenthesis) by 180 in my last post, that was a typo.

*March 17, 2008*

**Trigonometry**

Tim, This can be done very easily by BASICS of Tangent function: Tan has a period of PI, which is 180 degree. When you have a angle like 225, all you need to do is add or subtract multiples of 180(in this case, 150 itself) to get a common angle: 225-180 = 45 Tan(45)=1, since ...

*March 17, 2008*

**geometry**

surface area = 2x^2 + 4xh where x is the length of the side and h is the height. let x= 1/3h Then 224 = (2/9)h^2 + (4/3)h^2 solve it h = 12 then x = 1/3 h = 4 So the length is 4 and height is 12

*February 26, 2008*

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