Question : An example of an equality relation of two expressions in $x$. Which is not an identity, is:

Option 1: $(x+3)^{2}=x^{2}+6x+9$

Option 2: $(x+2y)^{3}=x^{3}+8y^{3}+6xy(x+2y)$

Option 3: $(x+2)^{2}=x^{2}+2x+4$

Option 4: $(x+3)(x–3)=x^{2}–9$

Question : If $x^{2}+\frac{1}{x^{2}}=1$, then, what is the value of $x^{48}+x^{42}+x^{36}+x^{30}+x^{24}+x^{18}+x^{12}+x^{6}+1$?

Option 1: – 9

Option 2: 0

Option 3: 1

Option 4: 9

Question : If $\frac {x^2+3x+1}{x^2–3x+1}=\frac{1}{2 }$, then the value of $(x+\frac{1}{x})$ is:

Option 1: 9

Option 2: –9

Option 3: 1

Option 4: 2

Question : If $x+\frac{1}{x}=1$, then the value of $x^{12}+x^9+x^6+x^3+1$ is:

Option 1: 1

Option 2: - 1

Option 3: 0

Option 4: - 2