a) Write ²
- 2x - 4 in the form (x + c)² + d.
What are the values of c and d?
b) Using your answer to part a), solve x²- 2x-4=0, giving your
answers in the form x = f± √g, where f and g are integers.

a Write 2x 4 in the form x c d What are the values of c and d b Using your answer to part a solve x 2x40 giving your answers in the form x f g where f and g are class=

Respuesta :

Answer:

see explanation

Step-by-step explanation:

(a)

x² - 2x - 4

using the method of completing the square

add/subtract ( half the coefficient of the x- term )² to x² - 2x

= x² + 2(- 1)x + 1 - 1 - 4

= (x - 1)² - 5

with c = - 1 and d = - 5

(b)

x² - 2x - 4 = 0 ← using result from (a) , that is

(x - 1)² - 5 = 0 ( add 5 to both sides )

(x - 1)² = 5 ( take the square root of both sides )

x - 1 = ± [tex]\sqrt{5}[/tex] ( add 1 to both sides )

x = 1 ± [tex]\sqrt{5}[/tex]