Question

If vector u has its initial point at (-7, 3) and its terminal point at (5,-6), u= ? i + ? j. If v= -11i + 3j, 2u -v = ? i+? j.

Answer 1

Answer:

a) $\vec u = 12i -9j$, b) $\vec r = 35i -21j$

Step-by-step explanation:

a) The vector u is:

$\vec u = [5-(-7)]i + [(-6)-3]j$

$\vec u = 12i -9j$

b) The resultant vector is:

$\vec r = 2\vec u - \vec v$

$\vec r = 2\cdot (12i -9j)-(-11i+3j)$

$\vec r = (24+11)i+ (-18-3)j$

$\vec r = 35i -21j$

Answer 2

Answer:

(a)

u = 12i  - 9j

(b)

35i - 21j

Step-by-step explanation:

Since the terminal point is (5,-6) and the initial point is (-7,3) then

u = (5,-6) - (-7,3) = (5- (-7) , -6 - 3 ) = ( 12 , -9 )

And you can write it in terms of i,j as follows

u = 12i  - 9j

Then

2u - v   =  24i  - 18j  +11i  - 3j = 35i - 21j