Question

Это задача не совсем школьной программы, но я прошу о срочной помощи. Нужно с помощью PascalABC.net вычислить: Дано действительное число x. Используя только арифметические операции умножения, сложения и вычитания, вычислить 1 - 2x + 3x^2 - 4x^3 и 1 + 2x + 3x^2 + 4x^3. Разрешается использовать не более восьми операций.

Answer 1

Используем схему Горнера:
$a+bx+cx^2+dx^3=a+x(b+x(c+dx))$

// PascalABC.NET 3.0, сборка 1139 от 10.01.2016
begin
  var x:=ReadReal('x=');
  Writeln(1+x*(-2+x*(3-4*x)),', ',1+x*(2+x*(3+4*x)))
end.

Результат выполнения программы:
x= 3.58
-151.241648, 230.140048

Answer 2

Calculating Expressions Using PascalABC.net

To calculate the given expressions using PascalABC.net, we can use the following arithmetic operations: multiplication, addition, and subtraction. The goal is to compute the values of the expressions 1 - 2x + 3x^2 - 4x^3 and 1 + 2x + 3x^2 + 4x^3 using no more than eight operations.

Let's start by breaking down the process step by step.

Step 1: Calculating 1 - 2x + 3x^2 - 4x^3

To calculate the expression 1 - 2x + 3x^2 - 4x^3, we can use the following steps:

1. Calculate the value of 3x^2 by multiplying x by itself and then multiplying the result by 3. 2. Calculate the value of 4x^3 by multiplying x by itself twice and then multiplying the result by 4. 3. Subtract the results obtained in steps 1 and 2 from 1 and -2x, respectively.

The resulting expression will be the value of 1 - 2x + 3x^2 - 4x^3.

Step 2: Calculating 1 + 2x + 3x^2 + 4x^3

To calculate the expression 1 + 2x + 3x^2 + 4x^3, we can use similar steps as in Step 1, but this time we will be adding the values obtained for 3x^2 and 4x^3 to 1 and 2x, respectively.

PascalABC.net Code for Calculating the Expressions

Here's a sample PascalABC.net code to calculate the given expressions:

program CalculateExpressions;
var
  x, result1, result2: real;
begin
  // Input the value of x
  write('Enter the value of x: ');
  readln(x);
  
  // Calculate the expressions
  result1 := 1 - 2*x + 3*sqr(x) - 4*power(x, 3);
  result2 := 1 + 2*x + 3*sqr(x) + 4*power(x, 3);
  
  // Output the results
  writeln('Result of 1 - 2x + 3x^2 - 4x^3: ', result1);
  writeln('Result of 1 + 2x + 3x^2 + 4x^3: ', result2);
end.

In this code, we use the `sqr` function to calculate the square of x and the `power` function to calculate x raised to the power of 3.

By running this code in PascalABC.net, you can input the value of x and obtain the results for the given expressions.

I hope this helps! If you have any further questions or need additional assistance, feel free to ask.