I'm puzzled on this one:
. . .Solve 2x² + 8x + 1 = 0 by completing the square.
So you subtract 1 to both sides, then divide by 2, getting:
. . .x² + 4x = -1/2
. . .(1/2 * 4)² = 4
. . .(x+2)² = 7/2 = (3 1/2)
. . .x + 2 = +/- √ (7/2)
. . .x = -2 +/- √ (7/2)
However the answer in the book is "x = -2 +/- √(14) / 2'. (The "2" is not inside the radical sign.) So they must have had √14/4 and squared the 4. But WHERE THE HECK did they get 14/4???
Thanks!
. . .Solve 2x² + 8x + 1 = 0 by completing the square.
So you subtract 1 to both sides, then divide by 2, getting:
. . .x² + 4x = -1/2
. . .(1/2 * 4)² = 4
. . .(x+2)² = 7/2 = (3 1/2)
. . .x + 2 = +/- √ (7/2)
. . .x = -2 +/- √ (7/2)
However the answer in the book is "x = -2 +/- √(14) / 2'. (The "2" is not inside the radical sign.) So they must have had √14/4 and squared the 4. But WHERE THE HECK did they get 14/4???
Thanks!