00:01
To determine the end derivative of x over x squared times the square to 4 minus x squared, we need to use trigonometric substitution, setting x equal to 2 sine of theta.
00:13
Now if x is 2 sine theta, then we should get x squared equal to 4 sine squared theta, and 4 minus x squared will be equal to 4 minus 4 sine squared theta.
00:30
And if we factor out the 4 at the right side, we should get 4 times 1 minus sine squared theta.
00:38
But since 1 minus sine squared theta is cosine squared theta, then 4 minus x squared is the same as 4 cosine squared theta.
00:47
Also, if we take the differential both sides for x equals 2 sine theta, from here we should get dx equal to 2 cosine theta, d theta.
00:58
So by trigonometric substitution, this is equal to the integral of 2 -sign theta over 4 -sign -squared theta times the square root of 4 -cosine -squared theta times 2 -cosine -theta -d -theta.
01:18
This gives us integral of 4 -sign -theta -cosine -theta -d -theta all over.
01:29
Over 4 sine squared theta times 2 cosine theta.
01:37
This cancels out, along with 4 sine theta at the bottom...