## anonymous 5 years ago 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

1. anonymous

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

2. anonymous

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

3. anonymous

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

4. anonymous

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

5. anonymous

shes an idiot

6. anonymous

thats whats off

7. anonymous

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

8. anonymous

w=sqrt [ 2+sqrt [6] ]