00:01
So in the given question what we are told us we have the function cost of cost of of a minus b is equal to 3 divided by 5 and we are also told that tan a times tan b is equal to 2.
00:28
So if these two are given, then we have a set of four options out of which we should choose which answers are correct and which are wrong.
00:40
Right.
00:41
So we have the options that cost a times cost b is equal to 1 by 5.
00:47
Option b says that sine a times sine b is equal to minus 2 divided by 5.
00:58
Option c says that cost of a plus b is equal to negative 1 by 5 and option d says sine a times sine b is equal to 4 divided by 5.
01:19
So now what we can do first is let's write let's take the relation that tan a times tan b is equal to 2.
01:30
We can write tan theta as sine theta divided by cos theta, right? and using this identity, what we can do over here is we can write tan a times tan b equal to 2 as sine a, sine b divided by cos a, cos b, cause a, cause b, is equal to 2.
02:00
Is equal to 2...