Joseph Fourier developed a method for modeling any function with a combination of sine and cosine functions. You can graph this with your calculator easily and watch the modeling in action. Make sure you're in radian mode and let c=1: f(x) = 4/(pi)*sin(x) + 4/(3pi)*sin(3x) + 4/(5pi)*sin(5x) + 4/(7pi)*sin(7x) + 4/(9pi)*sin(9x) + 4/(11pi)*sin(11x) Http://www.wolframalpha.com/ is also an excellent resource for graphing this function. Click here for convenience: https://www.wolframalpha.com/input?i=4%2F%28pi%29*sin%28x%29+%2B+4%2F%283pi%29*sin%283x%29+%2B+4%2F%285pi%29*sin%285x%29+%2B+4%2F%287pi%29*sin%287x%29+%2B+4%2F%289pi%29*sin%289x%29+%2B+4%2F%2811pi%29*sin%2811x%29