00:01
Okay, i'm hoping to show you how you can use your graphing calculator to solve things that would be kind of messy otherwise.
00:06
Let's look at a nice complicated problem.
00:09
How about complex fractions? we've got numbers all over the place.
00:18
Now, i can solve this by hand, multiply through by a common denominator of 20, come up with a solution.
00:24
That's all well and good.
00:26
But if i'm in a time crunch, how can i use my graphing calculator? basically, take your first y value and set it equal to the left.
00:36
Take another line in your calculator and set it equal to the right.
00:41
I want to know when this value and this value are the same.
00:45
In other words, i want to know where they cross.
00:48
So let's take a minute and type these in.
00:50
Y1 equals, and it was, i'm going to have to use parentheses, x minus 3, ending parentheses, divided by 5, and then a minus 1.
01:04
And it automatically knows to end it right there.
01:09
I'm trying to improve the lighting a little bit.
01:12
There we go.
01:13
It automatically knows to divide by 5 first and then do the minus 1.
01:18
And let's go look at the second half of the original equation.
01:21
X minus 5 over 4.
01:23
So i'm going to do parentheses again.
01:26
X minus 5 over 4.
01:28
Depending on your calculator, you can type in as a fraction.
01:32
It'll automatically change it.
01:34
This one's a little bit older model, but it all still works.
01:37
There's nothing wrong with this model of the calculator.
01:40
Now i'm going to hit graph, and i might have to do some editing.
01:43
We'll see how it looks.
01:47
Okay? see, i can't really tell where they're crossing over here.
01:51
So i can tell it's kind of here to the left, but i can't tell where.
01:56
So let me zoom around a little bit and see what happens.
02:01
Let me go to a window.
02:02
And i'm going to scoot over to the left.
02:05
How about negative 20? i don't even know if you need to go up to 10.
02:09
Let me graph again.
02:10
This is going to take a little plane to see they're crossing somewhere in there.
02:18
So somewhere in here.
02:19
Let me go to window again and edit it a little further.
02:23
Let's only go up to a y value of 1.
02:28
I'm just trying to really look at where they're crossing...