00:06
First i will draw the figure for these vectors.
00:16
Vector a is 70 degrees from ith direction, and this is jeth direction, and the magnitude of a is 3 .6, and vector b is 30 degrees from the negative side of the i, and it is 2 .4 in magnitude.
01:14
And if we, so the first part is to express a and b in terms of the unit vectors i and j.
01:23
So vector a is going to be 3 .6 cost 70 degrees i.
01:40
Since this is a vector, i will use the vector notation plus.
01:47
3 .6, sign 70 degrees j.
01:56
And a is going to be 1 .23i plus 3 .38 j.
02:42
And similarly we could write b, which is 2 .4.
02:56
So in this case, this is towards the negative side of the i and negative side of the j.
03:04
So we could either measure the angle from here, which is 210 degrees, or we could use the negative sign and consider just the 30 degrees.
03:19
So i will do just a negative sign, and 2 .4 cost 30, i minus 2 .4 sine 30.
03:44
And b is going to be minus 2 .08 i minus 1 .2 .2 .2 .2.
04:13
So these are the two vectors.
04:17
And then we're given vector c as 3 times a minus 4 times b...