00:01
In this question, we have a line y is equal to b that divides a region bounded by the graphs of the equations y is equals to 9 minus mod x and y is equal to 0 into two equal areas.
00:19
We are required to find the value of b.
00:23
So let's see how to solve this question.
00:25
First of all, let's draw the graph for y is equal to 9 minus mod x and y is equal to 0 and the graph is shown below.
00:34
So this is the graph for these two equations.
00:37
This red line represents y is equals to 9 minus mod x and this blue line represents y is equal to 0 and this black line represents y is equals to b.
00:54
Since the region bounded by the curves of y is equal to 9 minus mod x and y is equal to 0 lies between x is equal to minus 9.
01:05
And x is equals to 9 and it is symmetric about y x's.
01:11
Therefore, the expression to calculate area can be written as integration minus 9 to 9, 9 minus x d x.
01:25
So this will be equals to 2 into integration 0 to 9, 9 minus x d x.
01:32
So its integration will be equal to 2 into 9x.
01:36
2 into 9x minus x square upon 2 and the limits are 0 to 9.
01:44
Now substitute the limits.
01:46
So we get 2 into 81 minus 81 upon 2 which will be equals to 81.
01:57
And it is given that the line y equals to b divides this area into two equal parts...