Posts by Qun
Total # Posts: 21
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
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
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
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
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
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(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
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
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
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
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
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