For what values of t, if any, is given vector parallel to vector u = (4,-1): (8t, 2t)? and (1,t^2)?

Question

amistre64 · Answer

the vector would have to be a scalar of (4,-1) in order to be parallel to it

amistre64 · Answer

4 = 8t   
-1 = 2t

amistre64 · Answer

it can also be in the opposit direction and be parallel

amistre64 · Answer

-1/4 is the slope we want to obtain right?

anonymous · Answer

what is it possible?

anonymous · Answer

are you talking about the first one or second?

anonymous · Answer

b/c the second one I got -1/4 and I can't square root it

amistre64 · Answer

the second one cant be parallel; there is no hope of a negative slope with it

anonymous · Answer

and the first one I can't get a value that's works because one of them needs to be negative?

amistre64 · Answer

thats the way i see it as well; the cant hav the same direction as the original no matter what real values you plug in

anonymous · Answer

okay so the second one doesn't work I can't explain it

anonymous · Answer

I just can't completely find t when I tried

amistre64 · Answer

t^2 is always positive; no way to get a negative slope

anonymous · Answer

ohh that's makes more sense thanks!

amistre64 · Answer

youre welcome :)

anonymous · Answer

@amistre64: why has the vector be a scalar of (4,-1), it can be any scalar(4x,-1x) isn't it?

anonymous · Answer

allsmiles: is the question asking that both the vectors (8t,2t) and (1,t^2) should be parallel simultaneously or independently?

anonymous · Answer

The first one is always parallel, whatever the value of t be, the second one is parallel (or anti-parallel) when t = +- 1/2

amistre64 · Answer

a scalar of (4,-1) simply means that any scalar will do

amistre64 · Answer

t<8,2> != x<4,-1> no matter what you do to it right?

amistre64 · Answer

they are orthoganal vector

amistre64 · Answer

maybe not ortho; but no the same slope :)

anonymous · Answer

sry. what does <> mean?

amistre64 · Answer

<> denotes a vector as opposed to () which is a point

amistre64 · Answer

<3,5> is a vector;  (3,5) is a point

anonymous · Answer

Oh, so for no value of t are any of the two vecs parallel, isnt it?

amistre64 · Answer

correct

anonymous · Answer

for $$t \in R$$

amistre64 · Answer

the question asked shows point notation; but is assumed to be vectors :)

anonymous · Answer

thanks :)