how to calculate decibels

Function class $a =$_request["NUM1"]; $b =$_request["num2"]; $fuhao =$_request["Fuhao"]; Class cat{ Public function Jisuan ($a, $b, $fuhao) { Switch ($fuhao) { Case "+": $a + $b; Echo ' $a + $b = '. $a + $b; Break Case "-": $a-$b; Echo ' $a-$b = '. $a-$b; Break Case "*": $a * $b; Echo ' $a * $b = '. $a * $b; Break Case "/": $a/$b; echo ' $a/$b = '. $a/$b; Break } } } $cat 1=new Cat (); $cat 1->jisuan ($a, $b, $fuhao); ?> Reply to discussion (solution) It's working, you can

This question is so sad. I have been wa for a long time because I have misunderstood the question. Let's talk about how to solve the problem first: 1. When the two line segments do not want to be handed over, the result is 0.00. Parallel conditions are excluded here; 2. When either of the two line segments is parallel to the X axis, the result is also 0.00; 3. When the two line segments intersect but are in the same line (determined in parallel), the result is also 0.00; 4. Another situation is

If the current repayment date has not been paid off, the corresponding overdue interest will be generated, and the overdue interest shall be charged 0.05% per day for the unpaid amount of the present period. For example, October you want to return 10000 yuan, but before October 10, only 5000 yuan, on October 14 repayment, will generate overdue interest 10 yuan (formula: 5000 yuan x0.05%x4 days). In general, the overdue charges are also very low, at present the flower is rated at 3000 yua

Sometimes it is necessary to calculate the execution time of the command, which can be used, although the time command can be accurate to the millisecond level, but it is not possible to calculate the execution times of a heap of commands. You can also use the date command to calculate the time difference before and after the execution of a command, but using the

Tag: no 51ctoIn the game development often need to calculate the fan-shaped field of view or hit range.In fact, this is divided into two parts,The first part is within the fan range (i.e. regardless of the angle, in fact the circle range)The second part is in the fan angle rangeThe first part is very simple, vector3.distance (A, b); calculating distancesHere is the second part, within the fan angle range.Calculate if the monster is in your field of vi

These two tips, do not write do not know, a write scare! Are seemingly simple, actually do up on the Meng, have to think carefully, can write right! All have the date operation of the program should be careful Oh! Let's say the second one: 2. Calculate the age accurately according to the date of birth! The so-called calculation of the exact age is: birthday is not a day to grow one year old! Everyone commonly used, the number of years counted as age

... Editor's note: The week used to calculate the actual date is no problem. The principle is calculated based on the number of weeks known to be January 1, 1. If the day of the week is agreed on in your topic, you should pay attention to whether the day of the week is the same as the actual week, and if so, you need to consider a few days apart. If you feel that not enough fun, you can look at the following formula of the derivation process, so th

For some large files, sometimes you will need to calculate some of the content of the hash, the following function calculates the file tail 1 m, the middle jump 100M take 10K and file size hash value Public StaticString Calhash (String path)throwsIOException {File file=NewFile (path); if(!File.canread ())return""; if(File.length () ) { return""; } //FileInputStream in = new FileInputStream (file);Randomaccessfile in =NewRando

In a paper, there will be many questions, the points of each topic are different, how to quickly calculate the total score of all the topics?, we all know that in the spreadsheet can be easily calculated, in fact, in the WPS text can also use formulas to calculate the table, but the score of each question is not in the table, But scattered at the end of each topic, how to

Background It involves using Tomcat as a server in our daily development, but how much of a thread pool should we set up? And according to what principles to design this thread pool?Next, I will introduce how I design and calculate. Goal Determine the tomcat server thread pool size Specific methods It is well known that Tomcat accepts a request post-processing process that involves CPU and IO time. When IO waits, the C

, the greater the degree. The horizontal line is latitude, and the vertical line is longitude. Of course, we can calculate the equation of four yuan and two times. Both longitude and latitude are an angle. Longitude is a two-sided angle, which is the angle of two meridians. Because all meridians are the same length, in order to measure longitude to select a starting point, after 1884 years of International conference, decided to take the meridian line

What to do: a total of 12 months of JSON data (that is, 12 JSON files), a unit of JSON data is shown below. Read the data and find the annual and quarterly averages for each (over 100) cities. {"Time_point": "2014-01","Area": "* * *","AQI": "71","Pm2_5": "47","PM10": "69","Rank": "7"} I do this in two steps, read the JSON and import SQLite, find the database data as needed, and calculate the average. Import the database first the move is

There are two ways to calculate the time difference, one is to convert the times to minutes, one to convert the time to hours, the latter to divide so it is unavoidable to generate floating-point numbers, so we choose to convert to minutes to calculate.Title: Calculate their time difference at two points, for example, 1:50 and 3:21Define four variables to save the input timeDefault a time is less than B tim

When Excel establishes a financial report, it is usually necessary to calculate the relevant data, which is where we use the Excel program to facilitate the language. In the calculation of data, you need to establish a formula to achieve, and in the use of the formula, you need to refer to the value of the cell to calculate, then in Excel how to use the calculation formula for the operation? The following s

The calculation of personal income tax seems to be more complicated, it seems that it is impossible to use the VBA macro programming and only calculate by formula. In fact, the function formula provided by Excel can not only calculate the personal income tax, but also have a lot of flexibility: you can change the withholding tax base at will, arbitrarily change the deduction of tax subsection limit value an

The calculation of personal income tax seems to be more complicated, it seems that it is impossible to use the VBA macro programming and only calculate by formula. In fact, the function formula provided by Excel can not only calculate the personal income tax, but also have a lot of flexibility: you can change the withholding tax base at will, arbitrarily change the deduction of tax subsection limit value an

PHP used to generate machine code, to others to calculate the number to use, how to break?The following is the decrypted source code, before the source code is encrypted;This machine code will be generated. Machine code: BDC16D-1843D62D2956-2D2956EEF3A8-F3A8The science of the information looks like the MD5 turn 16 into the system what, there will be cracked master did not?$get _string = "TYCFTKHUVOJHJHPC";function Strtomd5_pass ($STR){Global $get _str

A recent project requires me to calculate the distance between two places, not a straight distance.That must use the relevant map API Ah, I chose the Baidu map I have set the incoming parameters of two, respectively, the origin and destination of the district (county) nameThe first is to use JS SDK to calculate, but the network requirements a little high, network stability can be calculated, instability wil

Shopping cart clicks can reduce or add items and automatically calculate prices: Shopping cart may have such a function, that is, click on the button can achieve a reduction or increase in the number of goods, and can be real-time calculation of the total price of goods, the following is a code example to introduce how to achieve this function, of course, the following simulation of the implementation of the shopping cart is difficult But you can get

Copy Code code as follows: /* | Author:yang Yu | @param char|int $start _date A valid date format, such as: 20091016,2009-10-16 | @param char|int $end _date ditto | @return weekend days between given dates */ function Get_weekend_days ($start _date, $end _date) { if (Strtotime ($start _date) > Strtotime ($end _date)) List ($start _date, $end _date) = Array ($end _date, $start _date); $start _reduce = $end _add = 0; $start _n = Date (' N ', Strtotime ($start _