Use the polynomial identity

22 + 2ax + a? = (a + a) (2 + a) to
rewrite 22
+ 42 + 4. Which polynomial
does this establish? (1 point)
022 + 42 + 4 = (2 - 4) (2 -
- 4)
0¢2+42+4=(¢=2)(2一2
002+4¢+4=1¢+④(¢+④
0∞2+4¢+4=1¢+2(¢+2

1 answer

To use the polynomial identity \( x^2 + 2ax + a^2 = (x + a)(x + a) \) to rewrite \( x^2 + 4x + 4 \), we first identify the coefficients in the expression \( x^2 + 4x + 4 \).

Here, we have:

  • The coefficient of \( x \) (which is \( 2a \)) is 4, so \( 2a = 4 \) ⇒ \( a = 2 \).
  • The constant term \( a^2 \) is 4, so \( a^2 = 4 \) ⇒ \( a = 2 \).

So we can proceed with the polynomial identity by substituting \( a = 2 \) into the identity.

Now we rewrite \( x^2 + 4x + 4 \) using \( a = 2 \): \[ x^2 + 4x + 4 = (x + 2)(x + 2) = (x + 2)^2 \]

This establishes that: \[ x^2 + 4x + 4 = (x + 2)^2 \]

Thus, the polynomial \( x^2 + 4x + 4 \) can be expressed as \((x + 2)^2\).