Ask AI: a⁴-9 factor

To factor the expression \( a^4 - 9 \), you can follow these steps: 1. Recognize that \( 9 \) can be written as \( 3^2 \): \[ a^4 - 9 = a^4 - 3^2 \] 2. Observe that this is a difference of squares: \[ a^4 - 3^2 = (a^2)^2 - 3^2 \] 3. Apply the difference of squares formula \( x^2 - y^2 = (x + y)(x - y) \): \[ (a^2)^2 - 3^2 = (a^2 + 3)(a^2 - 3) \] So, the factored form of the expression \( a^4 - 9 \) is: \[ (a^2 + 3)(a^2 - 3) \] While \( a^2 + 3 \) is already in its simplest form, \( a^2 - 3 \) can be further factored if needed into complex numbers, but over the real numbers, this is the completely factored form.