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Linear transformation input

Petrus

Well-known member
Feb 21, 2013
739
Hello,
this is something basic I have hard to understand and would like to have help!:)
this is a exemple from My book and I Dont understand the input!
"Let \(\displaystyle T: P_2->P_2\) be the linear transformation defines by \(\displaystyle T(P(x))=p(2x-1)\)
I Dont understand how this work
\(\displaystyle T(1)=1, T(x)=2x-1, T(x^2)=(2x-1)^2\)
Edit: if i think correct they think like this \(\displaystyle T(1)=T(x^0)=(2x-1)^0=1\)
Regards,
\(\displaystyle |\pi\rangle\)
 
Last edited:

Klaas van Aarsen

MHB Seeker
Staff member
Mar 5, 2012
8,774
Hello,
this is something basic I have hard to understand and would like to have help!:)
this is a exemple from My book and I Dont understand the input!
"Let \(\displaystyle T: P_2->P_2\) be the linear transformation defines by \(\displaystyle T(P(x))=p(2x-1)\)
I Dont understand how this work
\(\displaystyle T(1)=1, T(x)=2x-1, T(x^2)=(2x-1)^2\)

Regards,
\(\displaystyle |\pi\rangle\)
Hi Petrus!

I suspect that should be \(\displaystyle T(P(x))=P(2x-1)\).

If so, then for your first example, you would have P(x)=1.
So T(P(x)) = T(1).
And P(2x-1) = 1.
Therefore T(1) = 1.

In the second example, you would have P(x)=x.
So T(P(x)) = T(x).
And P(2x-1)=2x-1.
Therefore T(x) = 2x-1.

In the third example. you would have $P(x)=x^2$.
So $T(P(x)) = T(x^2)$.
And $P(2x-1) = (2x-1)^2$.
Therefore $T(x^2) = (2x-1)^2$.
 

Petrus

Well-known member
Feb 21, 2013
739
Hi Petrus!

I suspect that should be \(\displaystyle T(P(x))=P(2x-1)\).

If so, then for your first example, you would have P(x)=1.
So T(P(x)) = T(1).
And P(2x-1) = 1.
Therefore T(1) = 1.

In the second example, you would have P(x)=x.
So T(P(x)) = T(x).
And P(2x-1)=2x-1.
Therefore T(x) = 2x-1.

In the third example. you would have $P(x)=x^2$.
So $T(P(x)) = T(x^2)$.
And $P(2x-1) = (2x-1)^2$.
Therefore $T(x^2) = (2x-1)^2$.
Thank you! Evrything is clear now! Have a nice day!:)
By the way your suspect is correct!;)
Regards,
\(\displaystyle |\pi\rangle\)