Hi folks,

This year, we poured our love into updating our Precalculus course. We hope this course opens up opportunities for learners to experience success in college mathematics. Here's some of what you can expect to see.

• Go deeper with trigonometry. Did you know that trigonometry is useful for far more than finding side lengths and angles in right triangles? Not only can we use it with angles of all sorts (even reflex and negative angles), but we can also model cyclical data like weather patterns with trigonometry.
• Discover matrices, a flexible math tool we can use for everything from describing geometric transformations to solving systems of equations. Level up further by using matrices to represent and manipulate data like the relationships in a social network.
• Make decisions with probability. Which ways of making a "random" choice actually give everyone an equal chance and which ways introduce bias? Just how large does the prize need to be (relative to the ticket price and the chances of each outcome) for you to be likely to win more money than you lose by playing a game?

Are you a teacher? This part's for you.

We've added depth to the ways learners engage with Common Core advanced standards, drawing together multiple ways of thinking about each concept to reach more learners. For example, learners discover how multiplying complex numbers graphically reveals different properties than multiplying them symbolically.

Our updated unit structure spirals through key topics like trigonometry and inverse functions, helping learners see how they connect other precalculus topics. For example, as learners consider multiple force vectors acting on an object, they strategize about whether to convert vectors to component form or to apply the law of cosines.

Based on teacher requests, we've provided optional units on series and limits. We've made sure the other course content does not depend on those units, so teachers are free to include them or not while maintaining a coherent course. Progress in these optional units will not count toward or against course mastery.

You can learn anything!

Charlotte Auen

US mathematics content creator