This lecture covers the optimization of error in polynomial interpolation, focusing on minimizing the error by strategically placing interpolation points and using Chebyshev polynomials. The instructor explains the concept of equidistant points, optimal points, and the Chebyshev theorem. The lecture delves into the minimization of error by choosing the right interpolation points and discusses the Chebyshev polynomials' role in error minimization. The lecture concludes with a detailed explanation of the approximation process using polynomials and the importance of choosing the right coefficients for accurate evaluation.