Ken Tao is the MedSchoolCoach expert on MCAT, and will discuss trigonometry and help you remember sine and cos at 0, 30, 45, 60, and 90 degrees – as long as you know how to count to four!
Hey, welcome back to another MCAT Mnemonic Monday. I’m Ken and I’m an MCAT expert with MedSchoolCoach. Today we have an excellent physics mnemonic for you and it’s on trigonometry.
And this is a huge pain for a bunch of students having to remember what a sine 30 degrees, cosine of forty-five, sine of 60. While today’s mnemonic is going to help you out a bunch with this issue.
So here you can see we’ve got a table where we’ve got sine and cosine for these different thetas, different angles of zero, thirty, forty-five, sixty and ninety. And these are the main angles that you need to know for the exam. You don’t have to worry about what a sine of 13 degrees or cosine of forty-seven degrees. The MCAT doesn’t give you those weird angles. Really, you’re going to be seeing zero, thirty, forty-five, sixty, and ninety. All right.
So how does this work. Well the first thing you’re going to do is you’re going to do some brief setup for every single term, you’re going to have a square root of something over two.
Alright. Square root of something over two for every single term on this board. Square root and the numerator, two for the denominator. All right.
So once you’ve done this setup, then all you need to be able to do is count to four. Alright. So that means for sine in the numerator you’re going to put zero, one, two, three, four. And now we can just calculate the values.
The square root of zero is just zero. So zero over two a zero. So that means sine of zero degrees is zero. The square root of 1 is just one, and one over two is just 1/2, square root of 2 is just square root of 2. So that’s going to give us root over two. Square root of three is just square root of three. So that gives us square root of three over two. Square root of 4 is two. So 2 over two gives us one. So that’s four sine.
For cosine, we know it’s the opposite of sine, so instead of counting to four you’re going to count backwards. So we’re gonna go four, three, two, one, zero. And we’ve already calculated all the values. So we know this is going to be one. This is going to be square root of three over two. Square root of two over two. 1/2. And 0. And that’s it.
Right, so on your exam, if you want to quickly write down this table, it’s gonna save you a lot of time having to figure out what is sine and cosine of all of these different angles.