Answer:
The number would have to be added is 2
Step-by-step explanation:
To find the form of the completing square of the quadratic function:
- Divide the coefficient of x by 2
- Subtract the numerical term from the square of the quotient
Let us do these steps with our question
∵ x² - 2x - 1 = 0
→ Divide the coefficient of x by 2
∵ The coefficient of x is -2
∴ -2 ÷ 2 = -1
→ Square the -1
∵ (-1)² = 1
→ Subtract the numerical term from 1
∵ The numerical term = -1
∵ 1 - (-1) = 1 + 1 = 2
∴ We must add 2 to -1 to get 1
→ (x² - 2x - 1 + 2) - 2 = 0
→ (x² - 2x + 1) = 2
→ (x - 1)² = 2
The number would have to be added is 2