From 65e05b805e79dfbbdff6b9af5b0eaca92ce1518f Mon Sep 17 00:00:00 2001 From: Jagdish Prajapati Date: Wed, 20 Nov 2024 13:30:04 +0530 Subject: [PATCH] Syncing unsynced docs and metadata --- .../complex-numbers/.docs/instructions.md | 107 +++++++++++++++--- .../pythagorean-triplet/.meta/config.json | 4 +- 2 files changed, 91 insertions(+), 20 deletions(-) diff --git a/exercises/practice/complex-numbers/.docs/instructions.md b/exercises/practice/complex-numbers/.docs/instructions.md index 50b19aedf..2b8a7a49d 100644 --- a/exercises/practice/complex-numbers/.docs/instructions.md +++ b/exercises/practice/complex-numbers/.docs/instructions.md @@ -1,29 +1,100 @@ # Instructions -A complex number is a number in the form `a + b * i` where `a` and `b` are real and `i` satisfies `i^2 = -1`. +A **complex number** is expressed in the form `z = a + b * i`, where: -`a` is called the real part and `b` is called the imaginary part of `z`. -The conjugate of the number `a + b * i` is the number `a - b * i`. -The absolute value of a complex number `z = a + b * i` is a real number `|z| = sqrt(a^2 + b^2)`. The square of the absolute value `|z|^2` is the result of multiplication of `z` by its complex conjugate. +- `a` is the **real part** (a real number), -The sum/difference of two complex numbers involves adding/subtracting their real and imaginary parts separately: -`(a + i * b) + (c + i * d) = (a + c) + (b + d) * i`, -`(a + i * b) - (c + i * d) = (a - c) + (b - d) * i`. +- `b` is the **imaginary part** (also a real number), and -Multiplication result is by definition -`(a + i * b) * (c + i * d) = (a * c - b * d) + (b * c + a * d) * i`. +- `i` is the **imaginary unit** satisfying `i^2 = -1`. -The reciprocal of a non-zero complex number is -`1 / (a + i * b) = a/(a^2 + b^2) - b/(a^2 + b^2) * i`. +## Operations on Complex Numbers -Dividing a complex number `a + i * b` by another `c + i * d` gives: -`(a + i * b) / (c + i * d) = (a * c + b * d)/(c^2 + d^2) + (b * c - a * d)/(c^2 + d^2) * i`. +### Conjugate -Raising e to a complex exponent can be expressed as `e^(a + i * b) = e^a * e^(i * b)`, the last term of which is given by Euler's formula `e^(i * b) = cos(b) + i * sin(b)`. +The conjugate of the complex number `z = a + b * i` is given by: -Implement the following operations: +```text +zc = a - b * i +``` -- addition, subtraction, multiplication and division of two complex numbers, -- conjugate, absolute value, exponent of a given complex number. +### Absolute Value -Assume the programming language you are using does not have an implementation of complex numbers. +The absolute value (or modulus) of `z` is defined as: + +```text +|z| = sqrt(a^2 + b^2) +``` + +The square of the absolute value is computed as the product of `z` and its conjugate `zc`: + +```text +|z|^2 = z * zc = a^2 + b^2 +``` + +### Addition + +The sum of two complex numbers `z1 = a + b * i` and `z2 = c + d * i` is computed by adding their real and imaginary parts separately: + +```text +z1 + z2 = (a + b * i) + (c + d * i) + = (a + c) + (b + d) * i +``` + +### Subtraction + +The difference of two complex numbers is obtained by subtracting their respective parts: + +```text +z1 - z2 = (a + b * i) - (c + d * i) + = (a - c) + (b - d) * i +``` + +### Multiplication + +The product of two complex numbers is defined as: + +```text +z1 * z2 = (a + b * i) * (c + d * i) + = (a * c - b * d) + (b * c + a * d) * i +``` + +### Reciprocal + +The reciprocal of a non-zero complex number is given by: + +```text +1 / z = 1 / (a + b * i) + = a / (a^2 + b^2) - b / (a^2 + b^2) * i +``` + +### Division + +The division of one complex number by another is given by: + +```text +z1 / z2 = z1 * (1 / z2) + = (a + b * i) / (c + d * i) + = (a * c + b * d) / (c^2 + d^2) + (b * c - a * d) / (c^2 + d^2) * i +``` + +### Exponentiation + +Raising _e_ (the base of the natural logarithm) to a complex exponent can be expressed using Euler's formula: + +```text +e^(a + b * i) = e^a * e^(b * i) + = e^a * (cos(b) + i * sin(b)) +``` + +## Implementation Requirements + +Given that you should not use built-in support for complex numbers, implement the following operations: + +- **addition** of two complex numbers +- **subtraction** of two complex numbers +- **multiplication** of two complex numbers +- **division** of two complex numbers +- **conjugate** of a complex number +- **absolute value** of a complex number +- **exponentiation** of _e_ (the base of the natural logarithm) to a complex number diff --git a/exercises/practice/pythagorean-triplet/.meta/config.json b/exercises/practice/pythagorean-triplet/.meta/config.json index 6cfac6820..9905ac631 100644 --- a/exercises/practice/pythagorean-triplet/.meta/config.json +++ b/exercises/practice/pythagorean-triplet/.meta/config.json @@ -36,7 +36,7 @@ "build.gradle" ] }, - "blurb": "There exists exactly one Pythagorean triplet for which a + b + c = 1000. Find the triplet.", - "source": "Problem 9 at Project Euler", + "blurb": "Given an integer N, find all Pythagorean triplets for which a + b + c = N.", + "source": "A variation of Problem 9 from Project Euler", "source_url": "https://projecteuler.net/problem=9" }