 Hey everyone, welcome to Tutor Terrific. Today, I'm going to do a short tutorial for you on the TI-83 Plus. We're going to specifically look at converting between decimal degree farm and degrees, minutes, seconds farm or DMS. This would be something you would do if you're in a pre-calculus or trigonometry course, the equivalent course in integrated mathematics, maybe Math 3 or something like that. And these graphic calculators do the job very well. So let's say I have an angle and for example, 63.26, or 63.36, rather, degrees. Now, I haven't stated anything to the calculator except what the number is that I'm dealing with. I'm going to convert this number to degrees, minutes, seconds form using the calculator. Now, the way to get to DMS on the calculator, like this, this is true for the TI-83 Plus and the TI-84 Plus calculator line. We will select second apps and this gives us the angle menu and you can see the yellow word angle above the word apps. Here we have a couple options that we were going to deal with. We're not going to look at five, six or seven or even three, but one and two we'll look at later. For now, we are going to select number four, which says arrow DMS, which stands for convert the number before treated as an angle and convert it into degree, minutes, seconds form. So right now it's considering 63.36 as a decimal degree form of an angle. So when I press enter, I get the following. 63 degrees, 21 and this little dash, it's a little apostrophe that means minutes and it's a little double quote or apostrophe that means seconds. So this is 63 degrees, 21 minutes and 36 seconds. Now let me take a moment to explain for those of you who might be lost here what minutes and seconds are in angle language. A minute is a 60th of a degree and a second is a 60th of a minute. So this is like base 60 in a way. It's like base 60 counting of small subdivisions of an angle or in degrees. Notice how it doesn't matter what mode you're in for your angles. You could be in radian or degree mode and you will get the same result because we the calculator when you use that function will consider your number not to be in radian mode, but in degree mode. So let me do the calculation one more time 63.36 second apps for and enter. You get the exact same answer in degrees. So it doesn't matter what mode you're in for these operations. Now, what if you had an angle in your book or on your handout for your problems that was in degrees minutes seconds form to start and you need it in decimal degree form instead. Well, it's very easy on the calculator if you know where to find those particular symbols. So let me show you. Let's say you had 65 degrees two minutes and 17 seconds. 65 degrees two minutes and 17 seconds. So first I type 65. Then I go to that same menu for I found DMS second apps and I press this time number one see that little angle that little degree symbol. So now I have 65 degrees. Okay. Now what I'm going to do is type two because I have two minutes. I'm going to go to that same menu of second apps and press number two for that little apostrophe that little single quote. That means two minutes on this calculator. Now, if you go back and you type 17 and you go back to that same menu, you won't see seconds. It's not here. Which is a little frustrating to me. I don't know why it would be placed somewhere else. But it is. So I'm going to quit this menu and I'm going to show you. If I zoom in for you, it's dark green on this color combination for this calculator. Above plus it's dark green, which means you have to press the alpha button to get to it. So I'm going to press, I'm literally going to have to press alpha and the plus symbol and there it is minutes. 65 degrees, two minutes, 17 seconds. Now you might be saying, wait, where do I tell to convert to decimals? Well, you don't. You just press enter and it does it automatically. Aha, 65.03, etc. That is decimal degree form of this angle. Now again, I will prove to you that it doesn't matter what mode you're in. Currently I'm in degree mode. I will switch back to radiant mode. It's not going to give me a different answer here, guys. So quit this menu, bring up that same calculation again by pressing second enter and press enter. Same exact answer. It will be in degrees even though you're in radiant mode. Now this does not apply and it does matter what mode you're in when you are doing a trigonometric expression. For example, let's say right now I want to find cosine of six. I'm in, let's check, radiant mode. So of course that's going to find the cosine of six radians, 0.96. Six is near two pi, so it's close to one. But what if I get a little tricky here and I type six, but then I say second apps, one. Now according to me, I told you that that means degrees, but I'm in radiant mode. What happens? Boom. It converts it to degrees for you. So if you're in radiant mode, you could still plug in angles into trig functions in degrees and this is cosine of six degrees. It's different than the cosine of six radians. So guys, I hope this has been helpful to you to show you how to convert between dms and decimal degree form on your ti83 plus or your ti84 line of calculators. It's the same. All right, guys. Thanks for watching. This is Falconator signing out.