Course list http://www.c-jump.com/bcc/

Trigonometry

  1. Trigonometry
  2. Radians
  3. Pythagorean theorem
  4. sine cosine tangent
  5. Triginoimetric identities and formulas

1. Trigonometry

  • Trigonometry == relationships involving lengths and angles of triangles

  • Trigonometry works on a flat, two-dimensional surface (a plane)

  • Our application of trigonometry will be focusing on analyzing angles between vectors in space

    angles between vectors

2. Radians

  • Why use radians? For us, primarily, because C/C++ library functions such as sin(x), cos(x), etc. take angle in radians.

  • The formula to calculate the circumference of a circle is 2*radius*PI

  • One radian is equivalent to 180/PI degrees

  • There are 2*PI radians in a circle

    one radian 
  • 
/* radian, sin(), and cos() example */
#include <iostream>
#include <cmath>
using namespace std;

#define PI 3.14159265

int main ()
{
    double degrees = 30.0;
    double result = sin( degrees * PI / 180 );
    cout << "The sine of "<< degrees << " degrees is "<< result << "\n";
    result = cos( degrees * PI / 180 );
    cout << "The cosine of "<< degrees << " degrees is "<< result << "\n";
    // radians = (PI / 180) * degrees
    // degrees = radians / (PI / 180) = radians * 180 / PI
    cout << "One radian is "<< 180 / PI << " degrees\n";
    return 0;
}

/*Output:
The sine of 30 degrees is 0.5
The cosine of 30 degrees is 0.866025
One radian is 57.2958 degrees
*/

      degrees and radians

3. Pythagorean theorem

4. sine cosine tangent

5. Triginoimetric identities and formulas