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If 3+131=a+b3\dfrac{\sqrt{3} + 1}{\sqrt{3} - 1} = a + b\sqrt{3} ,find the values of 'a' and 'b'.

Rational Irrational Nos

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Answer

Given,

Equation : 3+131=a+b3\dfrac{\sqrt{3} + 1}{\sqrt{3} - 1} = a + b\sqrt{3}

Rationalizing the denominator of L.H.S. of the above equation :

3+131×3+13+1(3+1)2(3)212(3)2+12+2×3×1313+1+2324+2322(2+3)22+3.\Rightarrow \dfrac{\sqrt{3} + 1}{\sqrt{3} - 1} \times \dfrac{\sqrt{3} + 1}{\sqrt{3} + 1} \\[1em] \Rightarrow \dfrac{(\sqrt{3} + 1)^2}{(\sqrt{3})^2 - 1^2} \\[1em] \Rightarrow \dfrac{(\sqrt{3})^2 + 1^2 + 2 \times \sqrt{3} \times 1}{3 - 1} \\[1em] \Rightarrow \dfrac{3 + 1 + 2\sqrt{3}}{2} \\[1em] \Rightarrow \dfrac{4 + 2\sqrt{3}}{2} \\[1em] \Rightarrow \dfrac{2(2 + \sqrt{3})}{2} \\[1em] \Rightarrow 2 + \sqrt{3}.

Comparing 2+3 with a+b32 + \sqrt{3} \text{ with } a + b\sqrt{3}, we get :

a = 2 and b = 1.

Hence, a = 2 and b = 1.

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