Math, asked by nitin9721, 11 months ago

find the zero of the polynomial x^3-8​

Answers

Answered by leelasai1
14

Answer:

answer is 2

Step-by-step explanation:

x3-8 =. 0

x3=8

x3=2^3

then power will eliminated

x=2

Answered by hukam0685
0

The zeros of \bf {x}^{3}  - 8 are \bf 2, \:  - 1 \pm \: i \sqrt{3} .

Given:

  • A polynomial.
  •  {x}^{3}  - 8 \\

To find:

  • Find the zeros of polynomial.

Solution:

Concept to be used:

\bf {a}^{3}  -  {b}^{3}  = (a - b)( {a}^{2}  +a b +  {b}^{2} ) \\

Step 1:

Simplify the polynomial.

 {x}^{3}  - 8 =  {x}^{3}  -  {2}^{3}  \\

According to the identity.

\bf {x}^{3}  -  {2}^{3}  = (x - 2)( {x}^{2}  + 2x + 4) \\

Step 2:

Find the zeros of the polynomial.

Put the polynomial equal to zero.

(x - 2)( {x}^{2}  + 2x + 4)  = 0\\

So,

x - 2 = 0 \\

\bf x = 2 \\

or

 {x}^{2}  + 2x + 4 = 0 \\

Apply quadratic formula

\bf x_{1,2} =  \frac{ - b \pm \sqrt{ {b}^{2} - 4ac }   }{2a}  \\

x_{1,2} =  \frac{ - 2\pm \sqrt{ {( -2 )}^{2} - 4 \times 4 }   }{2}  \\

x_{1,2} =  \frac{ - 2\pm \sqrt{ 4 - 16 }   }{2}  \\

x_{1,2} =  \frac{ - 2\pm \sqrt{  - 12}   }{2}  \\

x_{1,2} =  \frac{ - 2\pm 2i \sqrt{3} }{2}  \\

\bf x_{1,2} =  - 1\pm i\sqrt{ 3} \\

Thus,

The zeros of \bf {x}^{3}  - 8 are \bf 2, \:  - 1 \pm \: i \sqrt{3}  \\

Learn more:

1) Find all the zeroes of the polynomial.

P(x) = x4 – 4x3 – 4x2 + 8x + 7 , if two of its zeroes are 

(3+root2)(3-root2)

https://brainly.in/question/18403070

2)The zeroes of the polynomial are p(x) = x² – 10x – 75

https://brainly.in/question/47993088

#SPJ3

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