Question

Find a • b.

a = 4i + 8j, b = -2i + 3j

Answer 1

@IMStuck

Answer 2

@jhonyy9

Answer 3

is there any other information dear..i feel it is incomplete

Answer 4

sorry..to find a.b it is fine

Answer 5

Do you know foil?

Answer 6

nope thats it and yes @BIOCRYSTAL

Answer 7

i have an answer but i want to see if it is right

Answer 8

@wade123 ..what's your answer?

Answer 9

Well, start out with parentheses around each function.

(4i+8)(-2i+3j)

Answer 10

32

Answer 11

Ummm- I don't think thirty two is right

Answer 12

wait let me try one more time, one sec

Answer 13

@wade123 ..post your answer..i vl tell you ..it is correct or not

Answer 14

You should have variables in your answer if I'm not mistaken

Answer 15

@1lorax2 nope, i dont think so

Answer 16

Is your i the imaginary number, or a variable?

Answer 17

yeah..no chance of getting a constant number...it should be with variables

Answer 18

none of my options have a variable..

Answer 19

If it's imaginary, he may be able to solve for j

Answer 20

Oh boy

Answer 21

In that case, let's foil like planned. remember that i^2=-1

Answer 22

okk on sec

Answer 23

<2, 11> @1lorax2

Answer 24

it has to be, i worked it out

Answer 25

Alright- that looks good to me. Great job!

Answer 26

did you solve it? thats what you got?

Answer 27

I plugged those numbers in, and they worked. I believe that's the correct answer

Answer 28

@BIOCRYSTAL you got that?

Answer 29

Dot product of two vector quantities have to be scalar .

Answer 30

a.b= |a||b|cos(theta)

Answer 31

is it 16

Answer 32

@SolomonZelman HELPPP

Answer 33

\(\Large \tt\color{blueviolet}{a.b=4.(-2)+8.3}\)

Answer 34

you just multiply the component of a and b together

Answer 35

and add

Answer 36

i got 16 , right? @xapproachesinfinity

Answer 37

that' you are answer

Answer 38

16 is right answer .