Question

Find all the zeroes of the cubic polynomials x3-4x+x2-4 if one of its zero is -1
plzzzz answer my question ​

Answer 1

Sᴏʟᴜᴛɪᴏɴ :-

given that, (-1) is the zeros of the cubic polynomial x³ - 4x + x² - 4 .

So, we can say that, (x +1) will divide the given polynomial completely .

Divisibility :-

x + 1)x³ + x² - 4x - 4(x² - 4

x³ + x²

-4x - 4

-4x - 4

0

→ Divisor = (x + 1)

→ Quotient = (x² - 4)

→ Remainder = 0

Now, we will find factors of Quotient..

→ x² - 4 = 0

→ x² = 4

→ x² = 2²

Square - root both sides,

→ x = ±2 .

Hence, All the zeros of given cubic polynomial are { (-1), (-2), 2 } .