---
id: c-math
title: "C Math Functions"
category: "Programming_Language"
status: "draft"
verification_status: "conceptual"
canonical_id: ""
aliases: ["math.h", "sqrt ceil floor pow", "C 수학 함수"]
duplicate_of: ""
source_trust_level: "B"
confidence_score: 0.83
created_at: 2026-07-04
updated_at: 2026-07-04
review_reason: ""
merge_history: []
tags: ["c", "programming-language", "w3schools", "math", "math.h"]
raw_sources: ["https://www.w3schools.com/c/c_math.php"]
applied_in: []
github_commit: ""
---

# [[C Math Functions]]

## 🎯 한 줄 통찰 (One-line insight)
`ceil()` and `floor()` both return a `float`/`double`, NOT an `int` — printing `ceil(1.4)` with `%f` still shows a decimal-formatted result (`2.000000`), meaning "rounding" in C's math library doesn't convert the value to an integer type; it just replaces the fractional part while preserving the floating-point representation, so further formatting or casting is still the caller's job. [S1]

## 🧠 핵심 개념 (Core concepts)
- **`<math.h>`** — required header for math functions beyond basic arithmetic operators. [S1]
- **`sqrt(x)`** — returns the square root of `x`. [S1]
- **`ceil(x)`** — rounds UP to the nearest integer value (still returned as a float/double). [S1]
- **`floor(x)`** — rounds DOWN to the nearest integer value (still returned as a float/double). [S1]
- **`pow(x, y)`** — returns x raised to the power of y (xʸ). [S1]

## 📖 세부 내용 (Details)
- Square root: `printf("%f", sqrt(16));`. [S1]
- Rounding up vs down on the same value: `printf("%f", ceil(1.4)); printf("%f", floor(1.4));` — ceil gives 2.000000, floor gives 1.000000. [S1]
- Exponentiation: `printf("%f", pow(4, 3));` — 4³ = 64. [S1]

## ⚖️ 모순 및 업데이트 (Contradictions & updates)
- 현재까지 발견된 모순 사항 없음 (No contradictions found in available sources).

## 🛠️ 적용 사례 (Applied in summary)
현재 발견된 실제 적용 사례가 없습니다 — sqrt/ceil/floor/pow는 게임 로직이나 그래픽 계산 등에서 흔히 결합해 쓰이는 기본 수학 함수 집합이다. [S1]

## 💻 코드 패턴 (Code patterns)
Rounding up and down, both still returned as floating-point values (C):
```c
#include <math.h>
printf("%f", ceil(1.4));  // 2.000000
printf("%f", floor(1.4)); // 1.000000
```

## ✅ 검증 상태 및 신뢰도
- **상태:** draft
- **검증 단계:** conceptual
- **출처 신뢰도:** B (W3Schools — widely used educational reference, not a primary standards body)
- **신뢰 점수:** 0.83
- **중복 검사 결과:** 신규 생성 (New discovery)

## 🔗 지식 그래프 (Knowledge Graph)
- **상위/루트:** [[C Tutorial]]
- **관련 개념:** [[C Strings Functions]], [[C Random Numbers]]
- **참조 맥락:** 수학 함수 — 난수 생성(Random Numbers) 챕터로 이어짐.

## 📚 출처 (Sources)
- [S1] W3Schools — C Math Functions — https://www.w3schools.com/c/c_math.php

## 📝 변경 이력 (Change history)
- 2026-07-04: Initial draft synthesized from the W3Schools "C Math Functions" page (Astra wiki-curation, P-Reinforce v3.1 format).