- #1

miglo

- 98

- 0

## Homework Statement

Suppose v_1,v_2,v_3,...v_n are vectors such that v_1 does not equal the zero vector

and v_2 not in span{v_1}, v_3 not in span{v_1,v_2}, v_n not in span{v_1,v_2,...v_(n-1)}

show that v_1,v_2,v_3,....,V_n are linearly independent.

## Homework Equations

linear independence, span

## The Attempt at a Solution

he gave us a hint, which was to use induction

heres what i have so far

for the base case n=1

v_1 does not equal 0

so for cv_1=0, c must equal 0 making v_1 linearly independent

then assume v_n is linearly independent to show v_(n+1) is linearly independent

since v_n is linearly independent, then v_1,v_2,v_3,v_(n-1) are all linearly independent as well, my books states this as a remark to linear independence so i assume i can use it

and v_(n+1) not in span{v_1,...v_n}

therefore c_1v_1+c_2v_2+....+c_nv_n+c_(n+1)v_(n+1)=0 if either

c_(n+1)v_(n+1)=-c_1v_1-c_2v_2-.....-c_nv_n

or c_(n+1)v_(n+1)=0

the former isnt true since its not in the span of all the vectors before it so then the latter must hold true

this is where i started doubting myself because then i would have to show that v_(n+1) is not zero and im unsure on how to do that, also im a beginner with proofs so im not even sure if im doing this correctly using induction

thanks in advance