Question

Find the dot product, a • b.

a = 6i + 5j, b = -5i + 4j

Answer 1

whats so hard about this @Nairz
6i+5j*-5i+4j

6i(-5i+4j) +5(5i+4j) can you solve this?

Answer 2

I haven't done this in a long time. Just need a refresher :)

Answer 3

so are u refreshed now

Answer 4

so just simplify that equation you wrote?

Answer 5

remember that i*j = 0

Answer 6

yeah multiply it
gonna show one
6i(-5i+4j)
6i*-5i + 6i*4j

then simply it, do it for both and then add subract, pretty basic

Answer 7

and when he says that i x j = 0 does that mean that 6i x 4j = 0? @snoo

Answer 8

@cwrw238 pl0x cum

Answer 9

6i x 4j = 24*ij = 24*0 = 0

Answer 10

^

Answer 11

do same with other one, @Nairz

Answer 12

doesn't
<x,y> dot <c,d>
mean xc+yd

Answer 13

ok thanks @snoo and @cwrw238

Answer 14

btw, call me daddy, i'm out :)

Answer 15

\[<6,5> \cdot <-5,4>=6(-5)+5(4)\]

Answer 16

omg yes.

Answer 17

so -30 + 20 or 10

Answer 18

well -30+20 is -10

Answer 19

oh whoops

Answer 20

i forgot to put in the - sign

Answer 21

i'm an old man i m sorry i was thinking of multiplying as adding, im so sorry dear

Answer 22

true @myininaya

Answer 23

I think we all get things a little mixed up sometimes. Math is huge subject after all.

Answer 24

thanks dear