Before learning calculus, it is important to have a strong mathematical foundation in algebra, geometry, and trigonometry. All of these types of mathematics are important in calculus, as you will be using algebra in every single operation, studying the building blocks of geometric shapes like circles, and using trigonometric functions like sine, cosine, and tangent. In addition, calculus is cumulative, meaning each new topic builds upon the topics before it. By having a firm grasp of algebra, geometry, and trigonometry, you’ll have an easier time applying them to new concepts.