Question

solve
w^4-4w²-2=0
cant figure out what i am doing wrong
u=w²
u²-4u-2=0
u=2-(sqrt)6 or u=2+(sqrt)6
w²=2-(sqrt)6 or w²=2+(sqrt)6
w=(sqrt)2+(sqrt)6, -(sqrt)2+(sqrt)6
tell me what i am doing wrong and how to fix it plz

Answer 1

nothing wrong at the beginning. you get
\[w^2=2+\sqrt{6}\]
\[w=\pm \sqrt{2+\sqrt{6}}\]

Answer 2

it is your final calculation that is off. you only need to take the square root of your solution for \[w^2\]

Answer 3

now
\[2-\sqrt{6}<0\] so if you are working only with real numbers this answer gives no solution for w

Answer 4

did this make sense? the only mistake you made was taking the square root of \[2+\sqrt{6}\]

Answer 5

shes an idiot

Answer 6

thats whats off

Answer 7

you have to put the square root sign over the whole expression

Answer 8

w=sqrt [ 2+sqrt [6] ]