Ackbach said:Definitely need to know your trig really well. See http://mathhelpboards.com/trigonometry-12/trigonometry-memorize-trigonometry-derive-35.html for some help on that. You need to know basic geometric facts like areas of squares, rectangles, triangles, and trapezoids. You need analytic geometry - so you're very familiar with going between the equation defining a function and its graph. You also need a significant mastery of basic algebra: finding roots of polynomials, solving equations including linear and quadratic. If you look at Stewart's Calculus book, he has a Diagnostic Exam in the beginning that should help you understand very well what the most important things to know are.
Precalculus is a branch of mathematics that prepares students for calculus. It covers topics such as functions, graphs, trigonometry, and algebraic equations.
Precalculus is important because it provides the necessary foundation for understanding and solving more complex mathematical problems in calculus and other advanced math courses.
The most important topics in precalculus include functions and their graphs, trigonometry, algebraic equations and inequalities, and exponential and logarithmic functions.
You can prepare for precalculus by reviewing basic algebra and geometry concepts, practicing solving equations and graphing functions, and familiarizing yourself with trigonometric concepts and identities.
Careers that require knowledge of precalculus include engineering, computer science, economics, and physics. It is also important for students planning to pursue a degree in mathematics or any other STEM field.