2007-05-21 02:24:36 · 10 answers · asked by rythemofdeparture 1 in Science & Mathematics ➔ Mathematics
x^2=-9
taking sq roots
x=3(-1)^1/2
x=3i where i=(-1)^1/2
2007-05-21 02:28:35 · answer #1 · answered by k2d 1 · 0⤊ 0⤋
This is equivalent to x = sqr(-9), which has no real answers.
Mathematicians have defined 'i' as an imaginary number with the property (amongst others) that i^2 = -1
So we can write sqr(-9) as sqr(i^2.3^2) so
sqr(-9) =+- i.3 or +- 3i
There is a lovely equation involving i:
e^(i.pi)+1 = 0 where e = the base of natural logs 2.7182818.... and pi = 3.14159......
2007-05-21 02:34:16 · answer #2 · answered by welcome news 6 · 0⤊ 0⤋
x^2 + 9 = 0
x^2 = -9
Take sqrt of both sides:
sqrt(x^2) = sqrt(-9)
x = +/- sqrt(-9)
Rewrite this as:
x = +/- sqrt(-1) * sqrt(9)
But sqrt(-1) is the imaginary number mathematically represented as i or j
therefore,
x = +/- sqrt(9)i
x = +3i or -3i
2007-05-21 02:42:10 · answer #3 · answered by Bamba 2 · 0⤊ 0⤋
x^2+9=o
collect like terms
x^2=-9
squre both sides
x=square of [-9]
x=-3
2007-05-21 02:29:14 · answer #4 · answered by xprof 3 · 0⤊ 2⤋
(x-3i)(x+3i) =x^2+3i-3i -9 ii=x^2+9
.
.
.here ii= -1
.
2007-05-21 03:47:25 · answer #5 · answered by Tuncay U 6 · 0⤊ 0⤋
x=sqrt(-9)
x = ±3i
2007-05-21 02:29:37 · answer #6 · answered by gudspeling 7 · 0⤊ 0⤋
Not possible. That would mean that X^2 = -9 and nothing squared can equal a negative number. :(
Oh, unless you are dealing in imaginary numbers. :)
2007-05-21 02:29:04 · answer #7 · answered by searching_please 6 · 0⤊ 1⤋
x² = - 9
x² = i² 9
x = ± 3i
2007-05-21 07:15:53 · answer #8 · answered by Como 7 · 0⤊ 0⤋
x = +/- 3*i
i = sqrt(-1)
2007-05-21 02:46:18 · answer #9 · answered by Dr D 7 · 0⤊ 0⤋
1)www.algebrahelp.com/worksheets/answers/equation/factoring.quiz
2)home.alltel.net/okrebs/page36.html
3)www.germantown.k12.wi.us/amybelle/Math%20pdf%20files/Math.Multiplication.An.pdf
2007-05-21 02:31:19 · answer #10 · answered by a_t_s_e_z 2 · 0⤊ 0⤋