Question

Find a cubic function with the given zeros.
\(\large\sqrt{7},~ -\sqrt{7}, ~-4\)

Answer 1

so are the roots

\[x = -\sqrt{7}, \sqrt{7}, 4\]

Answer 2

yes

Answer 3

-4 not 4

Answer 4

ok... then its simply

\[P(x) = (x - \sqrt{7})(x + \sqrt{7})(x - 4)\]

you should notice the 1st 2 binomials are the difference of 2 squares

hope it helps

Answer 5

ok... so if it's x = -4 the last binomial changes to (x + 4)

then just multiply them out

Answer 6

(x-\(\sqrt{7}\))(x+\(\sqrt{7}\))
\(x^2-x\sqrt{7}+x\sqrt{7}-\sqrt{49?~(idk)}\)

Answer 7

then multiply that by x+4 right?

Answer 8

is the last part of my equation right so far?

Answer 9

well yes the 1st and 2 binomials expand to

\[P(x) = (x^2 - 7)(x + 4) \]

Answer 10

Ok i was just making sure with everything in it first

Answer 11

(\(x^2-7)(x+4)\)
\(x^3+4x^2-7x-28\)

Answer 12

that's great... don't for get to let it equal something f(x) or something like that

Answer 13

ok thank you so much