Math

Introduction of benzalkonium chloride

vikasm — Thu, 06 Aug 2009 12:21:30 GMT

benzalkonium chloride is readily soluble in ethanol and acetone. Although dissolution in water is slow, aqueous solutions are easier to handle and are preferred. Solutions should be neutral to slightly alkaline, with colour ranging from colourless to a pale yellow. Solutions foam profusely when shaken, have a bitter taste and a faint almond-like odour which is only detectable in concentrated solutions.

Euclid contest, question 7a, 7b, and 9a

karooomph — Fri, 10 Apr 2009 01:01:44 GMT

believe it or not, I've actually given up on drawing diagrams.... So please see attached pic, should contain questions and diagram. Please do 7a, 7b, and 9a. Thanks! btw, 7a, hole punched out word is down, if you're ever wondering

Triangle trig

karooomph — Fri, 10 Apr 2009 00:44:44 GMT

In the diagram, triangle ABC is right-angled at C. Also, 2sinB = 3tanA. Determine the measure of angle A.

Its small. REAL small. Click to zoom.

Thanks

what is sinx = sin2x

karooomph — Sun, 12 Apr 2009 14:32:49 GMT

And finally to end my sporadic math question spree...!

what is sinx = sin2x?

how do you solve, and what is the answer?

and i dunno, what unit do you use, radians or degrees? Does one make the question easier than the other?

Thanks again!

Solving Inequalities

karooomph — Tue, 24 Mar 2009 02:08:15 GMT

find the solution set for :

|2x+9| <= |x-6|

sidenotes - <= means greater or equal to. and " | | " means absolute value.

Thanks

Circle theorem proof

karooomph — Fri, 27 Feb 2009 03:59:36 GMT

How do you prove that:

Inscribed angles subtended by the same arc of a circle are equal?

Diagram: http://i61.servimg.com/u/f61/13/61/85/57/circle12.jpg

combinations and permutations help

karooomph — Sun, 22 Feb 2009 16:11:29 GMT

sorry for the abundance of math questions lately, this will probably be the last for now. First read: A 5 x 6 rectangle is formed using 1 x1 squares, 5 going up, 6 across. How many rectangles of various sizes can be found in this figure? To solve: [firstly, squares are a special type of rectangles] Think of the grid as 7 vertical lines and 6 horizontal lines. To form a rectangle you must choose 2 vertical lines and 2 horizontal lines out of 6 possible. Each choice of 2 vertical ...

Pascal Contest, 2009, question 25

karooomph — Thu, 19 Feb 2009 03:46:45 GMT

Starting with the input (m,n), Machine A gives the output (n, m). Starting with the input (m,n), Machine B gives the output (m + 3n, n). Starting with the input (m,n), Machine C gives the output (m - 2n, n). Natalie starts with the pair (0,1) and inputs it into one of the machines. She takes the output and inputs it into any one of the machines. She continues to take the output that she receives and inputs it into any one of the machines. (For example, starting with (0,1), she could ...

Pascal Contest, 2009, question 21

karooomph — Thu, 19 Feb 2009 03:32:15 GMT

Alice rolls a standard 6-sided die. Bob rolls a second standard 6-sided die. Alice wins if the values differ by 1. What is the probability that Alice wins

AMC 12, 2009, question 12

karooomph — Wed, 11 Feb 2009 02:29:43 GMT

How many positive integers less than 1000 are 6 times the sum of their digits?

answer is 1 positive integer exists that satisfy the requirements. (54)

...I just don't know how you solve

thx

AMC 10, question 15

karooomph — Sun, 08 Feb 2009 15:05:00 GMT

Odell and Kershaw run for 30 minutes on a circular track. Odell runs clockwise at 250 m/min and uses the inner lane with a radius of 50 meters. Kershaw runs counterclockwise at 300 m/min and uses the outer lane with a radius of 60 meters, starting on the same radial line as Odell. How many times after the start do they pass each other?

btw, if anyone knows a good website with full solutions to these kind of contests, please post.

pheta, cos2pheta = 4cospheta, uncomplicated trig

karooomph — Sun, 08 Feb 2009 14:59:12 GMT

What is the sum of the values of θ between 0 and 2π inclusive satisfying cos2θ = cos4θ?

Elementary Statistics!

JFV — Sun, 18 Jan 2009 20:28:16 GMT

Hi all! May someone please solve for me the following two statistical problems: I would hugely appreciate the favor, thank you so much! First problem: Percipitation (inches) Find the Class Midpoint for each Find the Class Boundaries for each 1. 0.00-0.49 1. ? 1. ? 2. 0.50-0.99 2. ? 2. ? 3. 1.00-1.49 ...

Finding the area under a curve

chilipeppers827 — Mon, 12 Jan 2009 04:24:14 GMT

Is there a way to find the area under a curve without using left hand/right hand sums or a calculator?

Find the anti-derivative

funion987 — Tue, 13 Jan 2009 04:10:05 GMT

Find the anti-derivative of:

v(t) = ln(t²+1)

Or, find the area of the curve between t=0 and t=3 for the above function.

converting bases? (math, numbers)

karooomph — Thu, 08 Jan 2009 03:50:41 GMT

How would I convert 16 base 10 (normal) into base 5?

Would be you able to show me a solid way to convert various bases all the time?

(until, now, I have been using some self-logic-some-trial method in my head) and I've decided I have to find a reliable standard way to do this.

Thanks!

MAC1105, College Algebra!

JFV — Thu, 27 Nov 2008 16:51:21 GMT

Please, somebody solve this following exact value of expression using the corresponding properties of logarithms that matches with the problem:

e log[e]^(2) 9

Thank you so much.

God bless you and have a wonderful Thanksgiving Day!!!

MAC1105, College Algebra!

JFV — Wed, 26 Nov 2008 02:34:47 GMT

Please, write the following expression as a single logarithm:

log[2]((1)/(x))+log[2]((1)/(x^(2)))

Thank you very much!!!

MAC1105, College Algebra!

JFV — Wed, 26 Nov 2008 02:24:04 GMT

Write the following expression as a sum and/or difference of logarithms. Express powers as factors.

ln(xsqrt(1+x^(2))) x>0

Thank you very much!!!

MAC1105, College Algebra!

JFV — Wed, 26 Nov 2008 02:10:11 GMT

Please, somebody solve the following function for me with the following steps: f(x)=-ln(-x) Steps: 1. Find the domain of f 2. Graph f 3. From the graph, determine the range and any asymptotes of f 4. Find f^(-1) 5. Use f^(-1) to find the range of f 6. Graph f^(-1) Here, use www.mathway.com to solve the graphing parts of the function Thank you very much!!!

MAC1105, College Algebra!

JFV — Wed, 26 Nov 2008 01:34:43 GMT

Please solve the following equation for me: ln e^(-2x)=8

Thank you so much!

MAC1105!, college algebra

JFV — Wed, 19 Nov 2008 15:37:32 GMT

Can someone please solve the following quadratic function in full and in-depth explanations if possible, with the following ten corresponding and orderly steps if you do not mind please? I would hugely appreciate if anyone decided to take on this math probelm and plz asnwer it for me f(x)=2x^2+5x+3 Step 1: vertical ine test: Step 2: the domain: Step 3: The range: Step 4: the x and Y intercepts: Step 5: is it symmetric: Step 6: Function values: Step ...

MAc1105, college algebra

JFV — Wed, 19 Nov 2008 15:55:53 GMT

Somebody please answer the following polynomial function, with its following corresponding five steps in-depth? f(x)=(x+sqrt(3))^(2)(x-2)^(4) Step1: list each real zero and its multiplicity. Step 2: Determine whether the graph croses or touches the X-axis at each X-intercept. Step 3: Determine the behavior of the graph near each X-intercept. Step 4: Determine the maximum and minimum number of turning points on the graph. Step 5: Determine the end behavior and the power ...

MAC1105 Question!

JFV — Wed, 19 Nov 2008 03:31:23 GMT

Read carefully, then provide me with your most crediable answer. Alright, an equilateral triangle is inscribed in a circle of radius r. See the figure express the circumference c of the circle as a function of the length x of a side of the triangle.

Riemann Hypothesis

Coolv — Mon, 10 Nov 2008 15:02:43 GMT

We didn't exactly expect that the proof of Fermat's Last Theorem would come in the form of the modularity of semistable elliptic curves... Okay, some of us did.

But what about the Riemann Hypothesis? Is the multiplicative adelic approach valid, even when using adelic integration to control a k^* function supported on the ideles?