Question

What is the projection of (3,4) onto (3,1)?
(Points : 2)
1.3(3,1)

0.7(3,1)

1.3(2,4)

0.7(2,4)


according to the lesson it would be something like : vw/w but i think i would still be using a unit circle can someone help with this???

Answer 1

@Michele_Laino

Answer 2

are they two vectors?

Answer 3

yes, they are so far i have got (9,4)/(3,1 = 9 + 4 / sqrt4

Answer 4

the requested projection, is given by the subsequent formula:
if A=(3,4), B=(3,1), then, we have:
projection=
\[\large \frac{{A \cdot B}}{{B \cdot B}}B\]

Answer 5

where I used the canonical scalar product

Answer 6

so, substituting your data, I get:
\[\large \frac{{A \cdot B}}{{B \cdot B}}B = \frac{{9 + 4}}{{9 + 1}}\left( {3,1} \right) = ...?\]

Answer 7

sorry had to open the door for my dad you would get : 13/10 (3,1)

Answer 8

that's right!

Answer 9

and 13/10 = 1.3

Answer 10

ok!

Answer 11

i guess i was on the wrong page in the lesson then lol
the aswer would be 1.3 (3,1)

Answer 12

just to be sure i read this right in the lesson:

If the dot product of two nonzero vectors v1 and v2 is zero, what does this tell us?
(Points : 2)
v1 is perpendicular to v2.

v1 is a component of v2.

v1 is parallel to v2.

v1 = v2


the answer would be a right because i have c selected and i dont know why...

Answer 13

by definition is the first option, namely v_1 and v_2 are perpendicular each other

Answer 14

ok, lol thought that wasn't right, thank you for the help! :)

Answer 15

thank you! :)