 Let's move on to absolute values. You can see there what the absolute value is. Let me just click on this code cell You can see how I executed that. So it's LaTeC code Backslash left and upright, backslash right and upright there So that just shows you it's going to do these absolute value signs for me They have negative one negative a equals a So if you just look at that carefully, you'll see how LaTeC works It's not difficult and that gives me this beautiful Mathematic rendering of the notation there. So absolute a BS That's the absolute value say of negative 10. That's going to return just 10. There's also the app squared a BS To f squared so it's going to take the square of the absolute value for for us This is going to be a hundred Moving on to trigonometric functions, and you see there how I constructed that You can have a look at that and They are indeed all the trigonometric functions are there. I've just listed a few of them So just to introduce pi to you so we can say what is the sign of pi now? What is the sign of pi? What is pi is 180 degrees? What do you expect to see what is the sign? You might remember what the sign of pi is or the sign of 180 degrees gotta be zero and if we execute this We get something funny Now it says 1.22 times 10 to the power negative 16 That is what it's saying saying there now. This is peculiar to the fact that computers cannot really deal with Irrational numbers it's going to truncate them some way. It's got a cut it off some way. It cannot use values Without end. I mean pi has no end the value pi 3.141592653 et cetera et cetera et cetera It never stops, but the computer can't deal with that. It's got to stop some way and in this As I said, we're gonna have a look at types in using pi as such it is not the true value of pi and When doing the sign of this value that it does hold for pi it's still within its limits to do that calculation of this definitive number and It's going to do its best and it's going to throw out this Value of 1.2 times 10 to the power negative 16 which you have to accept as being zero That is just the way a computer works in and you have to live with that Now the next thing I want to show you is this you can force the fact that you want to deal with the degrees instead of Radians so I can say sine and I just can put a D at the end So now if I do the sine of 180 180 is really Integer, so it's going to do that properly for me. That is zero And just in case you were wondering you can also just very easily calculate the hypotenuse of a right angle triangle If one side is three the other side is four of the right angle or orthogonal sides It's going to work out the hypotenuse for us, which is very simply five One more thing for this part of the lesson I'm just going to show you how to use Sines the sine of a value if it's a positive value It's going to return plus one if it's a negative value is going to turn negative one and if it's a zero It's going to do that. So let's say what is the sign of? the sign of pi So we know it's going to return a positive as opposed to a zero Because of what we saw upstairs that the sign of pi is not going to return a zero for us but if we just simply said what is the sign of a hundred and eighty degrees but Remember, it's the sign in degrees. So we have to use the sin d function That's going to return a zero for us because it is neither positive nor negative