Linear transformation and polynomial function

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The discussion focuses on proving that the integral operator I, which maps polynomial functions of degree n to those of degree n+1, is an injective linear transformation. Participants suggest using polynomial functions of degree less than or equal to n to demonstrate the linearity properties of the transformation. They emphasize the need to show that the transformation satisfies the conditions L(x+y) = L(x) + L(y) and aL(x) = L(ax) for chosen polynomial functions. Additionally, there is a request for guidance on determining a basis for the image of I and finding the corresponding matrix representation. The conversation highlights the complexities involved in both proving linearity and identifying the necessary mathematical structures.
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Homework Statement


from calculus we know that ,for any polynomial function f : R-R of degree <= n,the fuction of I(f) :R-R ,s----\intf(u) du is a polynomial function of degree <=n+1
show that the map I: Pn--Pn+1 , f--I(f) is an injective linear transformation, determine a basis of the image of I and find the matrix M\inM(n+2)*(n+1)(R) that represents I with respect to the basis 1,t,...t^n of Pn and the basis 1,t,...t^(n+1) of Pn+1




Homework Equations





The Attempt at a Solution


can i use L(x+y)=L(x)+L(y) aL(x)=L(ax) to show linear transformation ? but for what value i can choose for x, y
for ''determine ...'' part i have no idea for it ,any help ?
 
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ak123456 said:

Homework Statement


from calculus we know that ,for any polynomial function f : R-R of degree <= n,the fuction of I(f) :R-R ,s----\intf(u) du is a polynomial function of degree <=n+1
show that the map I: Pn--Pn+1 , f--I(f) is an injective linear transformation, determine a basis of the image of I and find the matrix M\inM(n+2)*(n+1)(R) that represents I with respect to the basis 1,t,...t^n of Pn and the basis 1,t,...t^(n+1) of Pn+1

The Attempt at a Solution


can i use L(x+y)=L(x)+L(y) aL(x)=L(ax) to show linear transformation ?
No, you can't use these -- you have to show that they hold for this transformation. For x and y, use polynomial functions of degree <= n. For example, you could let f(x) = anxn + an-1xn-1 + an-2xn-2 + ... + a1x + a0, and g(x) = bnxn + bn-1xn-1 + bn-2xn-2 + ... + b1x + b0.
Then show that L(f + g) = L(f) + L(g) and that aL(f) = L(ax).




ak123456 said:
but for what value i can choose for x, y
for ''determine ...'' part i have no idea for it ,any help ?
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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