According to the desired accuracy, we determine the number of terms in the Fourier series and Legendre polynomials, then the Practical simplified formulae are obtained.
根据计算精度要求，确定福里哀级数和勒让德多项式的项数，从而得到实用简化公式。
2
All ordinary polynomials have series expansion of orthogonal polynomials, while Legendre polynomials, Hermite polynomials and Laguerre polynomials are special orthogonal polynomials.