Mathematics
18 Online
OpenStudy (anonymous):
How do I solve this binomial (factoring) : x^8-256x^4. Thank you :)
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (mertsj):
First factor out the common factor which is x^4
OpenStudy (anonymous):
ok :)
OpenStudy (anonymous):
x^4 *(x^2 - 16) *(x^2 + 16) = x^4 *(x-4)(x+4)(x^2 + 16)
OpenStudy (anonymous):
Is this the answer: x^4(x^2+16)?
OpenStudy (mertsj):
\[x ^{4}(x ^{4}-16) = x ^{4}(x ^{2}-4)(x ^{2}+4)=x ^{4}(x-2)(x+2)(x ^{2}+4)\]
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
So its the last one?
OpenStudy (mertsj):
x4(x−2)(x+2)(x2+4)
OpenStudy (anonymous):
Is a formula used to solve this?
OpenStudy (mertsj):
The difference of two squares.
OpenStudy (anonymous):
how did you get (x^2+4)
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (mertsj):
Use it twice. Once on the x^4-16 and again on x^2-4
OpenStudy (mertsj):
\[x ^{4}-16=(x ^{2}-4)(x ^{2}+4)\]
OpenStudy (anonymous):
@Mertsj .. it should be (x-4)(x+4) instead of (x-2)(x+2) .. you have to factor 256 which is 16^2
OpenStudy (anonymous):
x^4 - 256 = (x - 4)(x+4)(x^2 + 16)
OpenStudy (anonymous):
dont you take x^2 out of x^4 Mertsj
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (mertsj):
Add a factor of x^2+16)
OpenStudy (mertsj):
\[x ^{4}-256=(x ^{2}-16)(x ^{2}+16)=\]
OpenStudy (anonymous):
so wouldnt the final answer not have x^4, what is the forumula exactly?
OpenStudy (mertsj):
\[(x-4)(x+4)(x ^{2}+16)\]
OpenStudy (mertsj):
Then put the x^4 that we factored out in the front of it.
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (mertsj):
\[x ^{4}(x-4)(x+4)(x ^{2}+16)\]
OpenStudy (mertsj):
That's the final answer.
OpenStudy (anonymous):
cant you break down the 16 tho?
OpenStudy (mertsj):
No. The sum of two squares is not factorable in the set of real numbers.
OpenStudy (mertsj):
The difference of two squares is factorable but not the sum.
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
Thanks want to help me with another? :)
OpenStudy (anonymous):
its set up different
OpenStudy (mertsj):
Sure
OpenStudy (anonymous):
9x^2+64
OpenStudy (mertsj):
That is the sum of two squares and it cannot be factored.
Join the QuestionCove community and study together with friends!
Sign Up
OpenStudy (anonymous):
So its prime?
OpenStudy (mertsj):
yep
OpenStudy (anonymous):
ok, be right back :3
OpenStudy (anonymous):
im going to start a new question, this time i want to check an answer i got :)