Is Foerster's Alg II/Trig book sufficient as a precalc course if we spread it over 2 years and really dive deep into it, or would my ds need to do another precalc course before calculus? The reason for the dilemma - I had my son repeat Algebra II this past year because we originally used MUS AlgII and I wanted him to go deeper (he's interested in engineering). He barely got any wrong in MUS, and he gets few wrong with Foerster's - but, for unrelated reasons, he's only on chapter 7. He's a rising junion, so he doesn't have much time left in high school. Hoping I didn't do him a disservice by having him repeat Algebra II!