Answer:
71.6 degrees
Step-by-step explanation:
Given the vectors
u= <8,4> v = <9.-9> (5 points)
u*v = (8, 4)*(9, -9)
u*v = 8(9)+(4)(-9)
u*v = 72 - 36
u*v = 36
|u| = √8²+4²
|u| = √64+16
|u| = √80
|v| = √9²+9²
|v| = √81+81
|v| = √162
Using the formula
u*v = ||u||v| cos theta
36 = √80(√162)cos theta
36 = √12960 cos theta
cos theta = 36/√12960
cos theta = 36/113.8
cos theta = 0.3162
theta = arccos(0.3162)
theta = 71.56 degrees
Hence the angle between the given vectors to the nearest tenth of a
degree is 71.6 degrees
Answer:
x = -1
Step-by-step explanation:
AB + BC = AC = 28
the way from A to C goes through B.
so, the total way of A to C is the sum of the way from A to B and then from B to C.
=>
(5x + 10) + (2x + 25) = 28
7x + 35 = 28
7x = -7
x = -1
7*9
b. 63
v=5 i=1
5+1+1= 7
x=10
10-1= 9
9*7= 63
Answer:
<em>Assuming person A and person B are part of the 7 people</em>, there are 10 ways the 7 people can line up if A needs to be first or last and B needs to be in the middle.
Step-by-step explanation:
There are 2 places for A (first, last) and 5 places for B (anywhere but first or last). 2 x 5 = 10.
