Question

Given the vectors a = -2i+5j and b=3i+4j, determine:
1) 1/2 a 2) b-a 3) absolute value of b 4) a*b

Answer 1

1/2 a = 1/2 in the i direction and 1/2 in the j direction

so you get -1i + (5/2) j

Answer 2

b - a means you just subtract the numbers

(3-[-2]) i + (4-5) j

5i - 1j

Answer 3

a * b you just multiply the coefficients

(-2)(3) i + (5)(4) j

-6i + 20j

Answer 4

and absolute value of a vector doesn't make sense .. did it look like this |b| ?

Answer 5

yeah

Answer 6

that is the magnitude of the vector .. basically it is 3 in the horizontal direction and 4 in the vertical .. use pythagorean to get the magnitude

Answer 7

you should get |b| = 5

Answer 8

is there a direction for the 5?

Answer 9

a vector has both magnitude and direction. therefore, magnitude (the 5) wouldn't have direction, but the vector as a whole would of course.

Answer 10

thanks so much..this makes so much sense..its physics too

Answer 11

do you mind if i ask for your help with other problems...im not sure how to approach them

Answer 12

shoot

Answer 13

guess u figured them all out :)