x² - 4x + 1
Where am I messing up at
4(+-) square root(16-4(1)(1) divided by 2
then I get 4(+-) square root 6
How do you get 2(+-) square root 3 (as the final answer)
2006-12-12 06:32:07 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
x² - 4x + 1
x=(4+/-√(16-4))/2
x=2+/-(1/2)√12=2+/-√3
x=2+√3, 2-√3
2006-12-12 06:36:03 · answer #1 · answered by yupchagee 7 · 15⤊ 0⤋
OK, you obviously know the quadratic formula, but I'll reprint it for my own convenience. X = (-B +/- sqrt(B^2 - 4AC))/2A. Plugging in, you get X = (4 +/- sqrt(16 - 4))/2. So x = (4 +/- sqrt(12))/2. Now factor out 2^2 from the square root. x = (4 +/- 2sqrt(3))/2. Now go ahead and divide by 2, and you get x = 2 +/- sqrt(3), the right answer.
If I had to guess what you did wrong, I'd say probably you forgot that -B is also divided by 2A--that is, that in the formula X = (-B +/- sqrt(B^2 - 4AC))/2A, you forgot the outer set of parentheses.
2006-12-12 14:37:50 · answer #2 · answered by Amy F 5 · 0⤊ 0⤋
[ 4+-sqroot(16-4*1*1)]/2
dividing by 2 is the LAST thing you do. So you have (4+sqRt(12))/2 or (4-sqRt(12))/2
2006-12-12 14:36:47 · answer #3 · answered by Stu 2 · 0⤊ 0⤋
6 divided by 2 ha! ha! lol! Better not listen to me.
2006-12-12 14:37:10 · answer #4 · answered by Anonymous · 0⤊ 0⤋