In $$\triangle ABC, \angle C = 90^\circ$$ and $$CD$$ is perpendicular to $$AB$$ at $$D$$. If $$\frac{AD}{BD} = \sqrt{k}$$, then $$\frac{AC}{BC} = ?$$
In $$\triangle ABC, \angle C = 90^\circ$$ and $$CD$$ is perpendicular to $$AB$$ at $$D$$.
Given :Â $$\frac{AD}{BD} = \sqrt{k}$$
To find : $$\frac{AC}{BC} = ?$$
Solution : Let $$AD=\sqrt{k}$$ and $$BD=1$$
We know that, $$(CD)^2=(AD)\times(BD)$$
=> $$(CD)^2=\sqrt{k}\times1=\sqrt{k}$$
In right $$\triangle$$ BCD,
=> $$(BC)^2=(CD)^2+(BD)^2$$
=> $$(BC)^2=\sqrt{k}+1$$ -----------(i)
Similarly, $$(AC)^2=\sqrt{k}+k=\sqrt{k}(\sqrt{k}+1)$$ ---------------(ii)
Dividing equation (ii) by (i), we get :
=> $$(\frac{AC}{BC})^2=\frac{\sqrt{k}(\sqrt{k}+1)}{\sqrt{k}+1}$$
=> $$\frac{AC}{BC}=\sqrt[4]{k}$$
=> Ans - (D)
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