The term "Fundamental Theorems" often refers to key principles in various fields of mathematics. One of the most notable is the Fundamental Theorem of Calculus, which connects differentiation and integration, showing that these two operations are essentially inverse processes. This theorem provides a way to evaluate definite integrals using antiderivatives. Another important example is the Fundamental Theorem of Algebra, which states that every non-constant polynomial equation has at least one complex root. This theorem highlights the relationship between algebra and complex numbers, ensuring that polynomial equations can be solved within the set of complex numbers.