Question

(1 - i)2 is equal to
Option 1:
1
Option 2:
i
Option 3:
-2i
Option 4:
2-2i​

Answer 1

Solution:

Given to simplify,

= (1 - i)², note that here i = √-1

Using identity (a - b)² = a² - 2ab + b², expand,

= (1)² - 2 × 1 × i + (i)²

= 1 - 2i - 1 [i = √-1 or i² = -1]

= -2i

★ So, option C is the correct answer.

Answer:

• 2i

Additional Identities:

• (a + b)² = a² + 2ab + b²
• a² - b² = (a + b)(a - b)
• (a + b)³ = a³ + 3ab(a + b) + b³
• (a - b)³ = a³ - 3ab(a - b) - b³
• a³ + b³ = (a + b)(a² - ab + b²)
• a³ - b³ = (a - b)(a² + ab + b²)

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