is this correct?
1 +or- 3^1/2
2006-09-01 11:01:42 · 4 answers · asked by Olivia 4 in Science & Mathematics ➔ Mathematics
No , it's not correct
The correct answer is x= 1+or-5^1/2
which means x = 3.236068
or x = -1.236068
2006-09-01 11:14:26 · answer #1 · answered by phantom_man17 4 · 0⤊ 1⤋
Correct answers already given by several people, but here's a nice way of doing this one:
x^2 - 2x = 4
Add 1 to both sides:
x^2 - 2x + 1 = 5
(x - 1)^2 = 5
x -1 = + or - sqrt(5)
x = 1 + or - sqrt(5)
2006-09-01 19:19:11 · answer #2 · answered by Hy 7 · 0⤊ 0⤋
well JRussell
if f(x) = ax^2 + bx+ c & f(x)=x^2 - 2x - 4
so we have
a =1 , b= -2 & c = -4
â = b^2 - 4ac
â = (-2^2) - 4* 1*(-4) = 4 + 16 = 20
x1 = -b + ââ / 2a = -(-2) + â20 / 2*1 = 2+ 4.47 / 2 = 3.23
x2 = -b - ââ / 2a = -(-2) - â20 / 2*1 = 2- 4.47 / 2 = -1.23
2006-09-01 18:23:25 · answer #3 · answered by sweetie 5 · 0⤊ 0⤋
b^2 - 4ac = 4 + 16 = 20
1 plus or minus sqrt(5) is the answer.
2006-09-01 18:05:32 · answer #4 · answered by ? 6 · 0⤊ 0⤋