Final answer:
To show that (a + bi) ^2 = (a + b)(a - b) + 2abi, expand the left side of the equation and simplify.
Step-by-step explanation:
To show that (a + bi) ^2 = (a + b)(a - b) + 2abi, we can expand the left side of the equation and simplify:
(a + bi)(a + bi) = a^2 + 2abi + (bi)^2
Using the fact that (bi)^2 = -b^2, we can rewrite the equation as:
a^2 + 2abi - b^2 = a^2 + (a + b)(a - b) + 2abi
By combining like terms, we get:
(a + bi)^2 = (a + b)(a - b) + 2abi