Question

i need help with vectors!

Answer 1

1 - result is 7j

2: result is (-20,75)

Answer 2

what about this

Answer 3

btw for 2 i ended up with 55 because i needed only one number

Answer 4

-20+75 = 55

Answer 5

understand?

Answer 6

yes yes thats what i did haha

Answer 7

dot product is \[(x_{1}, y_{1}) . (x_{2},y_{2}) = (x_{1} \times x_{2}) + (y_{1} \times y_{2})\]
\[(2, 15) . (-10,5) = (2 \times(-10) +15 \times 5) = -20+75 = 75\]

Answer 8

yeah thats exactly what i did! i have another one that includes i

Answer 9

i think its 8i^2+-98i^2 which is -8+98 = 90 but it gives me wrong