Quote (fingerling @ 4 Feb 2014 07:58)
please work:
square root -8 times ( square root of -3 minus square root of -5)
I'm getting wrong answer.
<-8 ( <-3 - <-5)
< -8 x (-3) = < 24
< -8 x <-5 = 40
< 24-40 = < -16
i <16
not the right answer. I used < to symbolize square root.
do you mean sqrt(-8*[sqrt(-3)-sqrt(-5)]) ?
in that case you would start with sqrt(-8*[i*sqrt(3)-i*sqrt(5)])=sqrt(-8*i*(-1)*[sqrt(5)-sqrt(3)])=sqrt(8)*sqrt(i)*[sqrt(5)-sqrt(3)]
now you have the identiy sqrt(i)=[sqrt(2)/2]*(1+i) with sqrt(8)=sqrt(2)*2 you can simplify to
2*(1+i)*[sqrt(5)-sqrt(3)
and i leave the rest to you