Can you help me find my mistake? I'm factoring.
\[-2x^6=16\]
That's the equation, I'll show my work.
I subtracted 16 to the other side to get -2x^6-16=0 then i factored the GCF -2(x^6+8)=0 -2=0 makes 0 so that's one answer I got. Then i commenced factoring by cubes and got (x^2+2) (x^4-2x^2+4) which ends up being the same answers and i ended up with the answers x-0, \[\pm i \sqrt{2}\]
x=0 isn't one of the answers though so i did something wrong and don't know what.
Alright so you can use the Foil method or distribution method...Which do you prefer?
i have to factor these out
These are factoring polynomials
I know
What do you mean by foil or distribution?
Foil=First Outside Inside Last... meaning that you multiply the two things inside the parenthesis. (x^2 +2) (x^4-2x^2+4) I am going to use distribution x^2(x^4-2x^2+4) Can you do this?
Yes, I know how to. But i was told to take the equations and make them equal to zero to find the x-ints
but i factored out the 2 which made the 16 equal to 8
I subtracted 16 to the other side to get -2x^6-16=0 then i factored the GCF -2(x^6+8)=0 -2=0 makes 0 so that's one answer I got. Then i commenced factoring by cubes and got (x^2+2) (x^4-2x^2+4) which ends up being the same answers and i ended up with the answers x-0, ±i2√
\[\pm i \sqrt{2}\]
when you get to -2(x^6+8)=0 you divide both sides by -2 to get x^6 + 8 = 0 now you can factor it. (note: -2=0 is not true, and does not mean x=0 is a root)
oh because there is no x so -2=0 cannot happen
it just cancels out
in a way
Thank you, I know understand
x^4-2x^2+4=0 let y= x^2, and write this as y^2 -2y + 4 = 0 the roots are y= \(1 \pm \sqrt{3} \) and x = \( \pm \sqrt{1 \pm \sqrt{3} }\)
Thank you
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