Please help me with this question I will mark you as the best answer if correct
2 answers:
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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 = ± ( add 1 to both sides )
x = 1 ±
Notice the picture below
what we have, is really an angle, encroached by two sides
thus, use the Law of Cosines
what we have, is really an angle, encroached by two sides
thus, use the Law of Cosines