- #1
kash25
- 12
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Linear independence!?
Let {p, q} be linearly independent polynomials. Show that {p, q, pq} is linearly independent if and only if deg(p)>=1 and deg(q)>=1.
I am pretty sure the statement to prove is incorrect.
If we use deg(p) = -1 and deg(q) = -2, we can easily show that the two are linearly independent (consider the functions p(x) = 1/x and q(x) = 1/x^2).
We can have k/x + l/x^2 = 0
then kx + l = 0.
Then we can differentiate and get k = 0 and l = 0, which disproves the statement.
How does this make any sense?
Homework Statement
Let {p, q} be linearly independent polynomials. Show that {p, q, pq} is linearly independent if and only if deg(p)>=1 and deg(q)>=1.
The Attempt at a Solution
I am pretty sure the statement to prove is incorrect.
If we use deg(p) = -1 and deg(q) = -2, we can easily show that the two are linearly independent (consider the functions p(x) = 1/x and q(x) = 1/x^2).
We can have k/x + l/x^2 = 0
then kx + l = 0.
Then we can differentiate and get k = 0 and l = 0, which disproves the statement.
How does this make any sense?