SOLUTION: I need to find the answer to the sqrt of -8 ( sqrt -3 - sqrt 5) ugh. I got i sqrt 8 (i sqrt 3- sqrt 5) . Then I tried to simplify and did 4i sqrt 2 (i sqrt 3 - sqrt 5). Then I mult

Algebra ->  Real-numbers -> SOLUTION: I need to find the answer to the sqrt of -8 ( sqrt -3 - sqrt 5) ugh. I got i sqrt 8 (i sqrt 3- sqrt 5) . Then I tried to simplify and did 4i sqrt 2 (i sqrt 3 - sqrt 5). Then I mult      Log On


   

Question 1023089: I need to find the answer to the sqrt of -8 ( sqrt -3 - sqrt 5) ugh. I got i sqrt 8 (i sqrt 3- sqrt 5) . Then I tried to simplify and did 4i sqrt 2 (i sqrt 3 - sqrt 5). Then I multiplied it and got 4i^2 sqrt 6 - 4i sqrt 10. Then I subbed i^2 for -1 & ended up with -4 sqrt 6 - 4i sqrt 10. My book says I'm suppose to get -2 sqrt 6 - 2i sqrt 10. Please help
Found 2 solutions by addingup, MathTherapy:
Answer by addingup(3677) About Me  (Show Source):
You can put this solution on YOUR website!
the number i is defined to be equal to the square root of -1.
This means that i^2 is equal to -1.
You say you want to find the square root of -8.
sqr(-8) = sqr(-1)*sqr(8) (property of square roots)
sqr(-8) = i2.83

Answer by MathTherapy(10552) About Me  (Show Source):
You can put this solution on YOUR website!
I need to find the answer to the sqrt of -8 ( sqrt -3 - sqrt 5) ugh. I got i sqrt 8 (i sqrt 3- sqrt 5) . Then I tried to simplify and did 4i sqrt 2 (i sqrt 3 - sqrt 5). Then I multiplied it and got 4i^2 sqrt 6 - 4i sqrt 10. Then I subbed i^2 for -1 & ended up with -4 sqrt 6 - 4i sqrt 10. My book says I'm suppose to get -2 sqrt 6 - 2i sqrt 10. Please help
sqrt%28-+8%29%28sqrt%28-+3%29+-+sqrt%285%29%29

sqrt%28-+1+%2A+4+%2A+2%29%28sqrt%28-+1+%2A+3%29+-+sqrt%285%29%29%29

2i+%2A+sqrt%282%29%28i+%2A+sqrt%283%29+-+sqrt%285%29%29

%282i%5E2+%2A+sqrt%286%29%29+-+%282i+%2A+sqrt%2810%29%29

2%28-+1%29+%2A+sqrt%286%29+-+2i+%2A+sqrt%2810%29%29





As seen, sqrt%28-+8%29+=+sqrt%28-+1+%2A+4+%2A+2%29+=+2i+%2A+sqrt%282%29, not 4i+%2A+sqrt%282%29