00:01
Here in this problem we have given second theta is equal to minus 3 where theta is greater than 90 degree and smaller than 180 degrees.
00:15
And we are asked to find the value of 9 2 theta, cosine 2 theta and tangent 2 theta.
00:22
Since we have 2ceta is equal to minus 3 and we know that cosine theta is equal to 1 upon second theta.
00:34
Now we will substitute the value of second theta we get cosine theta is equal to minus 1 upon 3.
00:43
Now we will find the value of sine theta and we know that sine theta is equal to under root 1 minus cosine square theta.
00:56
By substituting the value of cosine square theta we get sine theta which is equal to under root 1 minus 1 upon 3 square.
01:06
By simplifying it we get 2 under root 2 upon 3.
01:13
Now we will find the value of sine 2 theta.
01:17
Since we know that sine 2 theta is equal to 2 into sine theta into cosine theta.
01:27
By substituting the value of sine theta and cosine theta we get 2 into 2 under root 2 upon 3 into minus 1 upon 3.
01:41
By simplifying it we get minus 4 into under root 2 upon 9...