00:01
In this problem, we're asked to find the real roots of the equation i've given here, first graphically, using the quadratic formula and using three iterations of the bisection method.
00:13
Okay.
00:15
So what we're going to do on this one is run the following function on matlab to get the graph, where y equals negative 5 times x 2 .5 times x 2 .5 times.
00:52
X plus 4 .5 end and we get x is equal to negative 2 0 .1 and 7 and then have it plot x versus x fx and you'll get your plot for this one the second here negative 0 .5 i need to do something here just hang on here i don't know if i can figure this out right now.
02:32
Hang on, i'm still right here.
02:46
So this one, i'm just going to do a real rough plot here.
02:52
So you can see what it should look like.
02:57
I'm going to go like this.
03:02
And this is going to be like one, two.
03:06
So i'm going to go right here.
03:08
And one, two, three, four, five, six, seven.
03:15
And it's going to go up to about two, up to about up here.
03:25
So i think it's like this.
03:29
This is super rough.
03:35
Okay, so you could get that to do this for you if you do the matlaf.
03:40
Then let's do the quadratic.
03:48
And our quadratic will be, which i never do this anymore, where a is equal to negative 0 .5, b is equal to 2 .5, and c is equal to 4 .5.
04:15
So we'll get x equals negative 2 .5 plus or minus 2 .5 squared minus 4 times 0 .5 times 4 .5.
04:36
We're going to divide that by 2 times 0 .5, negative 0 .5.
04:44
And this will give me 2 .5 plus or minus square root.
04:51
Of 15 .25 and that will equal 2 .5 plus or minus 3 .91.
05:10
So the positive sign of x and the negative sign of x, this will be negative 1 .405 and 6 .405.
05:27
And i do believe that's going to be correct.
05:46
By quadratics and c is by section i think with my xl will be equal to five and my x u is equal to ten let me verify that x5 and 10 okay very fun and so my f of five is 10.
06:29
Is negative 20 .5.
06:35
So the root will be between 5 and 10.
06:47
And so we're going to use 7 .5.
06:51
So the f of 7 .5 is negative 4 .875.
07:00
And this is my first iteration.
07:04
So 6 .405.
07:08
Minus 7 .5 divided by 6 .405 times 100 % 17 .09%.
07:21
And that's my error total.
07:24
And my true error will be 10 .5, 10 plus 5 times 100 will equal 33 .3%.
07:43
Then let's do our second iteration.
07:49
So here we're going to take our 5 plus 7 .5 divided by 2 equals 6 .25...