As you’ve probably guessed, my blog post today is all about probability! This is the topic that my Precalculus students have been studying lately. I decided to show you a few different problems that either involve combinations or where people THINK they have to use combinations when they actually don’t! This is advice that I taught myself to follow as I did more and more with probability, and I hope that it will help you to choose the easiest way to solve these types of problems too.

# Category: Pre-Calculus

# back at it!

I’ve been on a bit of a hiatus (I think I just got burned out after finals), but I’m back! My Precalc students have been studying conic sections with the most difficult problems being the ones where they have to write the equation based off of a description of the hyperbola, ellipse, etc. Since hyperbolas seem to give them the most trouble that is the kind that I picked for my video today…

I will see you back here again tomorrow! My plan is to finish off the rest of the school year with a blog post each day…we’ll see if I can stick to it!!

# it’s definitely winter

We woke up to -1 degrees this morning, brrr!! I was able to squeeze in enough time to record the following videos after I spent about 3 hours fine-tuning my schedule for finals! Every year I wonder which is more difficult…scheduling all of those hours of students or actually tutoring that many hours of students, lol! I think it’s a toss-up

Here is a video explaining a neat method for sketching polar graphs. This is what my honors Precalc students are doing this week…

And here is a video showing how to solve a trig equation that involves a total of 6 answers! This is what my regular Precalc students were just tested on…

# post office fun

I wish I was as good at using those self-service machines at the post office as I am at math! It would have saved me probably a half hour over waiting in line yesterday. I was almost late to tutor, and you probably noticed that I didn’t publish my Calculus post until midnight last night!!

Both my * honors and regular Precalc* students are synced up working on the chapter with trig identities right now. Both classes are

*so I created one video today showing a few examples of those. You have to be really familiar with your trig identities to make solving these equations much easier.*

**solving trig equations**

Have a wonderful Tuesday, and I’ll see you back here tomorrow for Advanced Algebra Trig!

# law of cosines…caution

Hello everyone! I missed posting yesterday, but it was for a good reason. I was giving out my first #mathsaverfavor! It was for a college stats student, and I will post the problem and explanation this Friday.

For today I decided to show why you should use caution when starting a law of cosines problem. I always tell my students to solve for the largest angle FIRST (using the law of cosines) when it’s an SSS triangle. That is because they ALWAYS like to switch over to the law of sines to find the second angle…which is fine! But if they haven’t planned ahead by finding the largest angle first, then the law of sines is not going to give them the correct answer if the second angle happens to be obtuse!!

So avoid all potential problems in SSS triangles by finding the largest angle first. I think that’s pretty easy to remember, and it will save you a lot of headaches down the road

My regular Precalc students are moving right along with double and half-angle trig identities. I’ve worked through two common problems using those identities in this video…