X^2 - 2X -1 = 1
更新1:
X^2 means X squared.
Algebra Equation Help.?
回答 (4)
2008-08-18 12:10 pm
✔ 最佳答案
x^2 - 2x - 1 = 1Add 2 to both sides :
x^2 - 2x + 1 = 3
Factorise left-hand side :
(x - 1)^2 = 3
Take the square root of both sides :
x - 1 = ± sqrt(3)
Add 1 to both sides :
x = 1 ± sqrt(3)
2008-08-18 6:00 pm
x^2 - 2x - 1 = 1
x^2 - 2x - 1 - 1 = 0
x^2 - 2x - 2 = 0
x = [-b 屉(b^2 - 4ac)]/2a
a = 1
b = -2
c = -2
x = [2 屉(4 + 8)]/2
x = [2 屉12]/2
x = [2 ±3.46]/2 (approx.)
x = [2 + 3.46]/2
x = 5.46/2
x = 2.73
x = [2 - 3.46]/2
x = -1.46/2
x = -0.73
â´ x â -0.73 , 2.73
x^2 - 2x - 1 - 1 = 0
x^2 - 2x - 2 = 0
x = [-b 屉(b^2 - 4ac)]/2a
a = 1
b = -2
c = -2
x = [2 屉(4 + 8)]/2
x = [2 屉12]/2
x = [2 ±3.46]/2 (approx.)
x = [2 + 3.46]/2
x = 5.46/2
x = 2.73
x = [2 - 3.46]/2
x = -1.46/2
x = -0.73
â´ x â -0.73 , 2.73
參考: Square Root Calculator
http://www.math.com/students/calculators/source/square-root.htm
2008-08-19 12:09 am
x² - 2x - 2 = 0
x = [ 2 ± â (4 + 8) ] / 2
x = [ 2 ± â (12) ] / 2
x = [ 2 ± 2â3 ] / 2
x = 1 ± â3
x = [ 2 ± â (4 + 8) ] / 2
x = [ 2 ± â (12) ] / 2
x = [ 2 ± 2â3 ] / 2
x = 1 ± â3
2008-08-18 5:59 pm
use the quadratic formula
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