Question : If $g=(2-\sqrt{3})$, what will be the value of $\left(g^3-\frac{1}{g^3}\right)$?
Option 1: $-30 \sqrt{3}$
Option 2: 52
Option 3: $30 \sqrt{3}$
Option 4: –52
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Correct Answer: $-30 \sqrt{3}$
Solution : Given, $g=(2-\sqrt{3})$ ⇒, $\frac{1}{g}=\frac{1}{2-\sqrt{3}}$ ⇒ $\frac{1}{g}=\frac{2+\sqrt{3}}{(2-\sqrt{3})(2+\sqrt{3})}$ ⇒ $\frac{1}{g}=2+\sqrt{3}$ $\left(g^3-\frac{1}{g^3}\right)=(g-\frac{1}{g})(g^2+\frac{1}{g^2}+g×\frac{1}{g})$ ⇒ $\left(g^3-\frac{1}{g^3}\right)=(2-\sqrt{3}-(2+\sqrt{3}))((4+3-4\sqrt{3})+(4+3+4\sqrt{3})+1)$ ⇒ $\left(g^3-\frac{1}{g^3}\right)=-2\sqrt{3}(15)$ ⇒ $\left(g^3-\frac{1}{g^3}\right)=-30\sqrt{3}$ Hence, the correct answer is $-30\sqrt{3}$.
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Question : If $\left(w+\frac{1}{w}\right)=6$, then what will be the value of $\left(w-\frac{1}{w}\right)?$
Option 1: $4 \sqrt{2}$
Option 2: $\sqrt{2}$
Option 3: $3 \sqrt{2}$
Option 4: $2 \sqrt{2}$
Question : If $A=30^{\circ}$, then find the value of $\frac{(2 \tan A)}{\left(1-\tan^2 A\right)}$.
Option 1: $4 \sqrt{3}$
Option 2: $\frac{3}{\sqrt{3}}$
Option 3: $3$
Option 4: $2 \sqrt{3}$
Question : If $x=5–\sqrt{21}$, the value of $\frac{\sqrt{x}}{\sqrt{32–2x}–\sqrt{21}}$ is:
Option 1: $\frac{1}{\sqrt2}(\sqrt{3}–\sqrt{7})$
Option 2: $\frac{1}{\sqrt2}(\sqrt{7}–\sqrt{3})$
Option 3: $\frac{1}{\sqrt2}(\sqrt{7}+\sqrt{3})$
Option 4: $\frac{1}{\sqrt2}(7–\sqrt{3})$
Question : If $x=(\sqrt{6}-1)^{\frac{1}{3}}$, then the value of $\left(x-\frac{1}{x}\right)^3+3\left(x-\frac{1}{x}\right)$ is:
Option 1: $\frac{2 \sqrt{6}-6}{5}$
Option 2: $\frac{4 \sqrt{6}-6}{5}$
Option 3: $\frac{4 \sqrt{6}-6}{3}$
Option 4: $\frac{4 \sqrt{3}-6}{5}$
Question : If $K+\frac{1}{K}=-3$, then what is the value of $\left(\frac{K^6+1}{K^3}\right)+\left(\frac{K^4+1}{K^2}\right)$?
Option 1: 27
Option 2: – 29
Option 3: 29
Option 4: – 27
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