00:02
Hi, in this question using nell's law we can write that sine by xan theta is equal to n2 by n1 and we already have all the values given in the diagram so we'll just substitute it here so that will be sine 45 divided by sine theta is equal to 1 .331 and sine 45 degree has a value of 1 by root 2.
00:45
So this will give the value of sine theta as 0 .531 or we can approximate that to 0 .55.
00:56
So, theta will be sine inverse 0 .5, which is equal to 30 degrees.
01:05
So now we have the value of theta.
01:09
Now, we'll consider triangle o, a, b in the diagram.
01:19
From that we can write o b is equal to x1, that is equal to side a, b into 4.
01:31
45 degrees and chord 45 degrees is equal to 1 and this value is equal to ab and we can say that ab is equal to y2 and from the diagram we have y2 as 2 .3 meters...