00:01
In this question we have two parts.
00:03
For part 1 we have fx is equal to 0, minus 1 is smaller than or equals to x is smaller than minus 1 upon 2.
00:16
Here sin 3 pi x minus 1 upon 2 is smaller than or equals to x is smaller than 1 upon.
00:25
Here at last we have 0, 1 upon 2 is smaller than or equals to x is smaller than 1.
00:31
Here f minus x is 0, minus 1 is smaller than or equals to minus x is smaller than minus 1 upon 2.
00:44
Here sin 3 pi minus x is minus 1 upon 2 is smaller than or equals to minus x is smaller than 1 upon 2.
00:55
Here 0, 1 upon 2 is smaller than or equals to minus x is smaller than 1.
01:02
Now here f minus x is equals to minus f x.
01:10
Hence f is odd function.
01:16
This is the answer for part 1.
01:20
Now we have part 2 for which as f is odd function so a n is equals to 0.
01:37
Now and b n is equals to 1 upon 1 minus 1 1 f x sin n pi x dx.
01:50
Here we are integrating it and we get minus 1 minus 1 upon 2 0 sin n pi x dx plus minus 1 upon 2 to 1 upon 2 sin 3 pi x sin n pi x dx plus 1 upon 2 1 0 sin n pi x dx.
02:30
Here we have b x b n is equals to minus 1 upon 2 to 1 upon 2 sin sin 3 pi x sin n pi x dx.
02:56
Now we are solving this then we then we get b n is equals to 2 minus 1 upon 2 to 1 upon 2 sin 3 pi x sin n pi x dx.
03:22
Here by integrating it we get b n is equals to 2 minus n minus 3 sin pi n plus 3 pi upon 2 plus minus n minus 3 sin n pi minus 3 pi upon 2 upon 2 pi n square minus 9...