trigonometric formulas

Giving intuitive proofs of the trigonometric formulas and formulas for the sum of the powers of natural numbers, which are brief, clear and beautiful, this paper attempts to connect the history with the pedagogy of mathematics and to probe into their relation(HPM for brevity).

作为数学教育改革的一种尝试，文章将数学发展的历史与数学教育相结合，给出了自然数幂和公式与三角公式的直观证明。

In the article,using the trigonometric power formulas, L Hospital rule,and integration by part,some evaluations of the improper integrals for positive integer are established.

利用三角函数幂公式、L’Hospital法则、分部积分公式和数学归纳法,得到含有三角函数的第一类广义积分∫∞0sinαxxndx的计算公式,其中n≥2且α≠0。

Evaluations of the first kind of improper integrals ∫~∞_0sin(θx)x~ndx for positive integer n≥1 and θ≠0 are established using the trigonometric power formulae, the L′Hospital rule, integration by part, and mathematical induction.

利用三角函数幂公式、L′Hospital法则、分部积分公式,得到含有三角函数的第一类广义积分integral from n=0 to ∞(((sin(θ_x))/x)~ndx)的计算公式,其中n≥1且θ≠0。

The first Dirichlet s integral is solved by trigonometric power reduced formulas and residue theory, namely, formula solutions have been obtained.

利用三角降次公式及留数解决了第一类Dirichlet积分问题,即给出了第一类Dirichlet积分的公式解。

Students may be confronted with difficulties in the application of complicated formulae of Spherical Trigonometry.

球面三角公式繁杂,学生在实际运用时感到困难。

Intuitive Proofs of the Trigonometric Formulas and Formulas for the Sum of the Powers of Natural Numbers;

自然数幂和公式与三角公式的几何证明——数学史与数学教学关系个案研究

The trigonometric terms should be changed by the substitution of the equations involving the double angles.

用倍角公式代换三角函数项。

Hermite Paratrigonometric Interpolation Formulae and Their Applications;

Hermite半三角插值公式及其应用

PRODUCTIVITY FORMULA OF HORIZONTAL WELLS IN FOUR SPOT AND TRIANGULAR PATTERNS

四点法和三角形井网水平井产能公式研究

Rebuilding Principle Formula of Optical Triangulation Method of Displacement Measurement in View of the Lambert′ Theory

基于朗伯定律重建光学三角法测位移原理公式

INTEGRAL CLASSIFICATION AND INTEGRAL FORMULAS FOR TRIANGULAR THIN-PLATE ELEMENTS

三角形薄板单元的积分分类和积分公式

Study on Management Mode of Highway ETC Network of the Changjiang River Delta;

长三角高速公路ETC联网收费管理模式研究

Research into the distance formula between related points in the triangle by means of vector method;

向量法研究三角形中相关点之间的距离公式

An exploration on the model of policy-oriented agricultural insurance company in the Pearl River Delta

珠江三角洲地区政策性农业保险公司模式探讨

A Ranking Method for a New Triangle Fuzzy Numbers

对一个三角模糊数距离测度公式的改进

To Explore on the Pattern of "Trinity" Environment Treatment--Based on the Angle of Market、Public、Government Cooperating;

“三位一体”的环境治理模式探索——基于市场、公众、政府三方协作的视角

Some high school students always are perplexed and at their wits' end when they do some exercises about the continue product of same kind trigonometric functions.

本文主要讲述三倍角公式在高中段数学教学中出现的一些同名三角函数连乘积计算中的应用。

Calculation formula and precision analysis were provided.

给出了计算三维角变形的理论公式,最后进行了精度分析。

Discussion to Standard Fuzzy Systems with Normal Trigonometric Membership Functions as Basic Functions

一类关于正规三角函数基的标准模糊系统逼近误差公式的讨论

Triangle Shirtwaist Company fire

三角女衫公司大火事件

hand-operated star-delta starter

手动式星三角起动机

Solving the spatial angle for formula"cosθ=cosθ_1 cosθ_2";

用公式cosθ=cosθ_1 cosθ_2求空间角