Question

4. [-12 Points) DETAILS SCALCET8 12.3.011. If u is a unit vector, find u v and u. w. (Assume v and w are also unit vectors.) u u v = Uw= 5. [-12 Points] DETAILS SCALCET8 12.3.015. Find the angle between the vectors. (First find an exact expression and then approximate to the nearest degree.) a = (7,2), b = (3,-1) exact approximate 6. [-/2 points) DETAILS SCALCET8 12.3.019. Find the angle between the vectors. (First find an exact expression and then approximate to the nearest degree.) a = 71 - 2j + k, b = 3i - k exact approximate

Answer 1

unit vector, find . if u is a av and u.w. ն E sol 73 ū. 13 that COS 0 We know u. Lullul coso lullvl = ū. ū >> cos(60) (10) u. V ul u.V u. W Also coso lullwi (10) cos(120) u. W ㅋ u.w 2 SO answers. = 1/4 U.V -ld 11 և. ա CS Scanned with CamScanner

approximate) <7,2> b= < 3,-1) 5 ) A aib Formula Cos o Sal lallbl lal (7)*+2) 149+4 153 Vio 971 (3)' +(-1) 21-2 = 19 a.b Ex3) + (2x-1) cos o 19 163110 19 1530 coð ( ut so 530 (exact) 34.38034472 o 34.38 (approximate) b 31-K 6 a = 7i-2j+k 49+4+1 - 54 lal (+)*+6)*+0? - 16 9+1 Ibl 3)+(0)+(-1" : a.b Ex3) + (-2x0) + (1x-1) 21 + 0-1 20. 11 20 20 Cos o √54510 540 20 cos 5540 (exact) 30.60889766 30.61 ° CS Scanned with CamScanner