How would I solve these?
1. x^2 - 3x + 5 = 0
2. x^2 - 3x = -5
3. 2x^2 - 8x = -16
2007-11-24 12:22:12 · 3 answers · asked by net_phantom16 2 in Science & Mathematics ➔ Mathematics
I can solve the equation all the way to the final step...but there is a - in the radical, and my teacher said thats a no no
2007-11-24 12:36:06 · update #1
If there's a minus sign in the radical, pull it outside as a factor of i, and your teacher should be happy.
For example, the third one is x^2 -4x + 8 = 0.
Plugging that into the quadratic formula, you get that the roots are 2 +/- sqrt(-4)
Well, the square root of -4 is 2i, so the answer is 2 +/- 2i
2007-11-24 16:02:07 · answer #1 · answered by Curt Monash 7 · 0⤊ 0⤋
i^2=-1
so if you need to find the square root of -8
it equals sqrt(8i^2), Or 2i rt2
2007-11-24 20:31:40 · answer #2 · answered by Mr. Mojo Risin' 3 · 0⤊ 0⤋
you could use the quadratic equation-
(-b +/- sqrt(b^2-4ac))/2a
usually its a weird decimal, but it will get you the right answer(s)
2007-11-24 20:27:50 · answer #3 · answered by geeklovesturkeysandwiches 2 · 0⤊ 0⤋