How do you factor \[{{x}^{3}}+27=0\]?
Answer
627k+ views
Hint: From the given question, we have been asked to factor the given equation \[{{x}^{3}}+27=0\]. We can factor the given equation by doing some transformations to the given equation. First we have to find one factor for the given equation. Then, we can get remaining factors for the given cubic polynomial.
Complete step-by-step solution:
From the question, we have been given that \[{{x}^{3}}+27=0\]
We know that we can write \[27\] as \[{{3}^{3}}\].
By doing this, we get the given equation as \[{{x}^{3}}+{{3}^{3}}=0\]
Now, on the left hand side of the equation, we get a standard polynomial which is in the form of \[{{a}^{3}}+{{b}^{3}}\].
For the standard polynomial l\[{{a}^{3}}+{{b}^{3}}\], we know that \[\left( a+b \right)\] is one of the factor for the given polynomial.
By comparing the coefficients, we get \[\left( x+3 \right)\] as a factor for the given cubic polynomial \[{{x}^{3}}+27=0\].
Now, from the question, we have been given that \[{{x}^{3}}+27=0\]
Now, as of process,
Add \[3{{x}^{2}},-3{{x}^{2}},9x,-9x\] on the left hand side of the given cubic polynomial.
By doing this, we get the above equation as \[{{x}^{3}}+3{{x}^{2}}-3{{x}^{2}}-9x+9x+27=0\]
Now, by taking the common terms out, we get the equation as \[{{x}^{2}}\left( x+3 \right)-3x\left( x+3 \right)+9\left( x+3 \right)=0\]
\[\Rightarrow \left( x+3 \right)\left( {{x}^{2}}-3x+9 \right)=0\]
Hence, the given cubic polynomial is factored.
As we have been already discussed above, by using some simple transformations, we get the given cubic polynomial factored.
Note: We should be well aware of the factorization process of polynomials. We should be well known about the process of factoring the cubic polynomial. Also, we should identify whether the given polynomial is in the form of a standard polynomial or not. Also, we should be very careful while finding the factors. We have a formulae in built given as ${{a}^{3}}+{{b}^{3}}=\left( a+b \right)\left( {{a}^{2}}+{{b}^{2}}-ab \right)$ .
Complete step-by-step solution:
From the question, we have been given that \[{{x}^{3}}+27=0\]
We know that we can write \[27\] as \[{{3}^{3}}\].
By doing this, we get the given equation as \[{{x}^{3}}+{{3}^{3}}=0\]
Now, on the left hand side of the equation, we get a standard polynomial which is in the form of \[{{a}^{3}}+{{b}^{3}}\].
For the standard polynomial l\[{{a}^{3}}+{{b}^{3}}\], we know that \[\left( a+b \right)\] is one of the factor for the given polynomial.
By comparing the coefficients, we get \[\left( x+3 \right)\] as a factor for the given cubic polynomial \[{{x}^{3}}+27=0\].
Now, from the question, we have been given that \[{{x}^{3}}+27=0\]
Now, as of process,
Add \[3{{x}^{2}},-3{{x}^{2}},9x,-9x\] on the left hand side of the given cubic polynomial.
By doing this, we get the above equation as \[{{x}^{3}}+3{{x}^{2}}-3{{x}^{2}}-9x+9x+27=0\]
Now, by taking the common terms out, we get the equation as \[{{x}^{2}}\left( x+3 \right)-3x\left( x+3 \right)+9\left( x+3 \right)=0\]
\[\Rightarrow \left( x+3 \right)\left( {{x}^{2}}-3x+9 \right)=0\]
Hence, the given cubic polynomial is factored.
As we have been already discussed above, by using some simple transformations, we get the given cubic polynomial factored.
Note: We should be well aware of the factorization process of polynomials. We should be well known about the process of factoring the cubic polynomial. Also, we should identify whether the given polynomial is in the form of a standard polynomial or not. Also, we should be very careful while finding the factors. We have a formulae in built given as ${{a}^{3}}+{{b}^{3}}=\left( a+b \right)\left( {{a}^{2}}+{{b}^{2}}-ab \right)$ .
Recently Updated Pages
If x a + bt + ct2 where x is in meters and t is in class 11 physics CBSE

A car covers the first half distance between two places class 11 physics CBSE

The resultant of two vectors overrightarrow P and overrightarrow class 11 physics CBSE

Find the value of cos 135 class 11 maths CBSE

A mass M is held in place by an applied force F and class 11 physics CBSE

A solution of glucose in water is labelled as 10 dfracwv class 11 chemistry CBSE

Trending doubts
One Metric ton is equal to kg A 10000 B 1000 C 100 class 11 physics CBSE

Find the value of the expression given below sin 30circ class 11 maths CBSE

What do you mean by retardation What is its SI uni class 11 physics CBSE

Draw a diagram of nephron and explain its structur class 11 biology CBSE

10 examples of friction in our daily life

Difference between physical and chemical change class 11 chemistry CBSE

