Let's talk about frustration with high school math. As a home educator, you have the power to make things better. You can decide on the methods and curriculum that best fit your child. The best part of homeschooling is our ability to adapt. There are three things you can do when a student experiences frustration with math.
If your student is constantly frustrated with math, or has trouble finishing assignments, there may be a curriculum mismatch. While you can't make a student love math, you can make it palatable. If your student is doing well in math, but is frustrated, sometimes the child is just using a curriculum that doesn't fit. The blessing of homeschooling high school is that we have a variety of great math curricula to choose from. There are many great math programs that I love and work well. Look over this article, High School Math at Home, to help you choose between some of the top-rated programs.
Once you have chosen the curriculum that fits, decide if you should modify assignments. Each student needs a different number of practice problems before they learn the concepts. You aren't teaching a group of 30 students, you are only teaching one student. You can decide how many practice problems your one student needs. If a student is quite good at math, you could try reducing the number of practice problems to make the assignments fit better.
Try using the odd or even practice problems. Correct those problems. If the child gets 80%-90% correct, that's all the problems that are needed for mastery. After doing just half the practice problems your student could be done for the day. If the student does NOT get 80%-90% right, then he or she should do the other half of the problems. This option will sometimes work with perfectionists, or slow-as-molasses math nerds.
Trying using the hardest practice problems each day. With this option, assign just the last 5 or 6 problems in the practice set. Those are usually the hardest problems. If your student gets all of those 5 or 6 questions right, they probably don't need to practice on all the other easier problems. This option will sometimes work with gifted students who are working above grade level, or for those who really enjoy math.
Try starting at the right place in the textbook. When changing a math curriculum, you don't start over, no matter how much the publisher might say you need to buy all their books. Instead, you purchase the book you think he should start in, and then pre-test to determine WHERE in the book he should start. Like this: day 1, give end of chapter test 1. If he gets 80% correct, then day 2 you give the end of chapter test 2, and if he gets 80% right move on. Next day, day 3, you give him the end of chapter test 3, and if he gets 80% right the next day you give him the end of chapter test 4. Once you get to the chapter that he does NOT already know the answers to, then THAT is the chapter in the textbook you start to work on.
I hope that helps you as the home educator, and also maximizes your child's options for the future. Take care!