(1+i)^2
Let's calculate: (1 + i)2
ⓘ Raising a sum to a positive integer power means multiplying it by itself as many times as the exponent indicates: (1 + i)2 = (1 + i)×(1 + i)
(1 + i)×(1 + i)
ⓘ Multiply each term of the sum by the other factor, using the distributive law: (1 + i)×(1 + i) = 1×1 + 1×i + i×1 + i×i
1×1 + 1×i + i×1 + i×i
ⓘ Perform multiplications before additions and subtractions: 1×1 = 1■Multiplying powers with the same base adds the exponents: i×i = i2
1 + i + i + i2
ⓘ Group like terms by adding their coefficients: i + i = 2i■i2 = -1, so integer powers of i reduce to 1, i, -1 or -i: i2 = -1
1 + 2i -1
ⓘ Start from 1 and move back 1 on the number line, down to zero: 1 -1 = 0
0 + 2i
ⓘ Adding 0 changes nothing: 0 + 2i = 2i
▶Result:   2i