Understanding FOIL: Expanding (x-2)^2
The FOIL method is a handy tool for expanding binomials (expressions with two terms). Let's use it to expand the expression (x-2)^2.
What is FOIL?
FOIL stands for First, Outer, Inner, Last. It's a mnemonic device to help you remember the order to multiply terms when expanding binomials:
- First: Multiply the first terms of each binomial.
- Outer: Multiply the outer terms of the binomials.
- Inner: Multiply the inner terms of the binomials.
- Last: Multiply the last terms of each binomial.
Applying FOIL to (x-2)^2
Since (x-2)^2 is the same as (x-2)(x-2), let's apply FOIL:
- First: x * x = x^2
- Outer: x * -2 = -2x
- Inner: -2 * x = -2x
- Last: -2 * -2 = 4
Now, combine the terms:
x^2 - 2x - 2x + 4
Simplify by combining like terms:
x^2 - 4x + 4
Conclusion
Therefore, (x-2)^2 expanded using the FOIL method is x^2 - 4x + 4. Remember, FOIL is a simple but powerful tool for expanding binomials.