formula

What is a formula to get a three dimensional vector B lying on the plane perpendicular to a vector A? That is, given a vector A, what is a formula f(angle,modulus) which gives a vector that is perpendicular to A, with said modulus and rotated through an angle? If the two vectors are perpendicular then their dot product is zero. So: v1(x1, y1, z1), v2(x2, y2, z2) . => x1 * x2 + y1 * y2 + z1 * z2 = 0 You know (x1, y1, z1) . Put arbitrary x2 and y2 and you will receive the corresponding z2 : z1 * z2 = -x1 * x2 - y1 * y2 => z2 = (-x1 * x2 - y1 * y2) / z1 Be aware if z1 is 0 . Then you are in the

How to calculate the number of working days between two dates in JavaScript using moment.js. I have a working formula that calculate these days, but the formula does not satisfies all conditions: here is my code: var start= moment(data[x].start_date); var end= moment(data[x].est_end_date); var difference= end.diff(start, 'days'); var workingDays= Math.round((difference/7)*5); //data[x] is for iterating over a loop I get five days per 7 days here because saturday and sunday are considered as NON-Working days, but this formula will fail if the count of the days were started from sunday or

I am currently learning python through a video tutorial on youtube, and have come up against a formula I cannot seem to grasp, as nothing looks right to me. The basic concept of the excersise is to make a mortgage calculator that asks the user to input 3 pieces of information, Loan Amount, Interest Rate, and Loan Term (years) then it calculates the monthly payments to the user. here is my code: __author__ = 'Rick' # This program calculates monthly repayments on an interest rate loan/mortgage. loanAmount = input("How much do you want to borrow? \n") interestRate = input("What is the interest

I'm currently looking at different solutions getting 2 dimensional mathematical formulas into webpages. I think that the wikipedia solution (generating png images from LaTeX sourcecode) is good enough until we get support for MathML in webbrowsers. I suddenly realized that it might be possible to create a Google Charts API equivalent for mathformulas. Has this already been done? Is it even possible due to the strange characters involved in LaTeX-code? I would like to hit an url like latex2png.org/api/?eq="E = mc^2" and get the following response: edit: Thanks for the answers sofar. However, I

How are you all doing? I have a little problem with my code. When I stop my timer program, it will say "Done!" since I set it to "Done", but I would like to display the remaining time instead of the word "Done". Like for example if I the original time set is 4000 Seconds and I stopped at 3000 seconds I want to display the current time which is 3000 when stopping it instead of the word "Done". Can you guys help me out? I would really appreciate it. Here's my code: import java.awt.event.*; import java.awt.*; import javax.swing.*; public class CountdownTimer extends JFrame { JLabel promptLabel,

I have a calculation which I am unable to crack. Lets say my Cost Price is 300. I want to sell the item at No Profit or No Loss. My total commission/expenses will be 30%. So it means i need to sell the item at 390. But if I do 390 - 30% = 273. How can I see the item, so that if I minus 30% to it. My Revenue will still be 300. the formula you want is =300/0.7 or =300/(1-30%) basically it is 300= x*(1-.30) where the (1-.30) is the amount that wants to be kept after the commision of 30%. Solving for x we get the above formula. You want Sell Price - 30% Sell Price = Cost Price. Combining the left