They're actually both the same value. Using the quadratic formula gives
[ -b 屉(b^2 - 4ac) ] / 2a
[ 4 屉(16 - 4*2*3) ] / (2*2)
[ 4 屉(16 - 24) ] / 4
[ 4 ± â-8 ] / 4
[ 4 ± â(-2*4) ] / 4
[ 4 ± 2â-2 ] / 4
[ 4 ± 2iâ2 ] / 4
If you decide to fully distribute the 4 in the denominator, you get 1 ± ((iâ2) / 2), which is what you yourself got. If you divide the top and bottom by 2, you get what's in the book.
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Verified answer
x= -b ± √b^2 - 4ac ALL OVER (2a)
x= 4 ± √16 - 4(2)(3)
ALL OVER 2(2)
x= 4 ± √-8
ALL OVER 4
x= 4 ± 2i√2
ALL OVER 4
x= 2 ± i√2
ALL OVER 2
They're actually both the same value. Using the quadratic formula gives
[ -b 屉(b^2 - 4ac) ] / 2a
[ 4 屉(16 - 4*2*3) ] / (2*2)
[ 4 屉(16 - 24) ] / 4
[ 4 ± â-8 ] / 4
[ 4 ± â(-2*4) ] / 4
[ 4 ± 2â-2 ] / 4
[ 4 ± 2iâ2 ] / 4
If you decide to fully distribute the 4 in the denominator, you get 1 ± ((iâ2) / 2), which is what you yourself got. If you divide the top and bottom by 2, you get what's in the book.
2x^2 - 4x + 3 = 0
a = 2
b = -4
c = 3
then it is the opposite of b plus and minus the square root of b^2 - 4ac all divided by 2a so plug and chug!
4 +- SR of -4^2 - 4(2)(3)/ 2(2)
4 = - SR of 16 - 24/4
4 plus and minus the square root of -8/4
No solution because you can not square root a negative number.
I am not sure how they came up with the answer in the back of the book.
Using the formula, we get x = (4 +/- sqrt(16-24))/4, or (2 +/- sqrt(-2))/2. Both you and the book are correct.
x = (-b+-sqrt(b^2-4ac))/(2a)
= (-(-4)+-sqrt(16-24))/(2*2)
= (4+-sqrt(4*2*(-1)))/(2*2)
= (4+-2i*sqrt(2))/(2*2)
= (2*(2+-i*sqrt(2)))/(2*2)
= (2+-i*sqrt(2))/2
=1+-(i*sqrt(2))/2)