# Math Help - Question regarding Polynomials

1. ## Question regarding Polynomials

Use the fourth degree equation ax^4 + bx^3 + cx^2 + dx + e = 0 whose roots are A,B,C,D to verify that

1) the equation P(x/m) = 0 has roots m times those of P(x) = 0.

Thank you.

2. Originally Posted by noobonastick
Use the fourth degree equation ax^4 + bx^3 + cx^2 + dx + e = 0 whose roots are A,B,C,D to verify that

1) the equation P(x/m) = 0 has roots m times those of P(x) = 0.

Thank you.
Let x be a root of P(x)=0, put y=mx, then P(y/m)=P(x)=0, so mx is a root of P(x/m).

CB

3. Originally Posted by CaptainBlack
Let x be a root of P(x)=0, put y=mx, then P(y/m)=P(x)=0, so mx is a root of P(x/m).
sorry I dont understand the logic... can you elaborate?

4. Originally Posted by noobonastick
sorry I dont understand the logic... can you elaborate?
I have shown that if x is a root of P(x), then mx is a root of P(x/m).

What else do you need?

(note implicit assumption that m != 0)

CB