00:01
So in the given question we are told to find the value of the expression sine pi by 6 plus i .kos pi by 6 raised to the power 7.
00:12
And we are given a few options in the question.
00:15
So what we are going to do first is to take use the demo overs theorem in order to simplify this expression, right? and according to the demover's theorem, sign sorry cost theta plus i sine theta raised to sum power n can be found as cost of n theta plus i sign of n theta so let's use this theorem over here so we can see that in the demover theorem we have the expression cost theta plus i sine theta so let's take the expression sine pi by six plus i cos pi by six and write this expression as i times sine pi by six divided by i plus cos pi by six right we can write it like this so what is one by i one by i is equal to multiply the numerator and the denominator with i.
01:34
So we will have i divided by i square and since i is equal to the square root of minus 1, i squared is equal to minus 1, right? so this is i divided by minus 1 which is minus i.
01:49
So 1 by i has a value of minus i.
01:54
So these are the results that we are going to use over here.
01:59
And we can see that we can write the expression this expression as i times minus sine minus i minus i sine pi by six plus cos pi by six which we can rewrite and write as cos pi by six right as cos pi by six minus i sine five by six right and now let's use the demo verse theorem.
02:35
So we have just taken sine pi by 6 plus i cost pi by 6 raised to the power 7...