Question Number 212630 by efronzo1 last updated on 19/Oct/24
Commented by efronzo1 last updated on 19/Oct/24
$$\:\: \\ $$
Answered by mr W last updated on 19/Oct/24
Commented by mr W last updated on 19/Oct/24
$$\mathrm{tan}\:\alpha=\frac{{h}−\frac{{b}}{\mathrm{2}}}{\frac{{b}}{\mathrm{2}}}=\frac{\mathrm{2}{h}−{b}}{{b}} \\ $$$$\mathrm{tan}\:\mathrm{2}\alpha=\frac{{a}−\frac{{b}}{\mathrm{2}}}{{h}}=\frac{\mathrm{2}{a}−{b}}{\mathrm{2}{h}} \\ $$$$\frac{\mathrm{2}{a}−{b}}{\mathrm{2}{h}}=\frac{\mathrm{2}×\frac{\mathrm{2}{h}−{b}}{{b}}}{\mathrm{1}−\left(\frac{\mathrm{2}{h}−{b}}{{b}}\right)^{\mathrm{2}} } \\ $$$$\frac{\mathrm{2}{a}−{b}}{\mathrm{2}{h}}=\frac{\mathrm{2}×\frac{\mathrm{2}{h}−{b}}{{b}}}{\mathrm{1}−\left(\frac{\mathrm{2}{h}−{b}}{{b}}\right)^{\mathrm{2}} } \\ $$$${let}\:\lambda=\frac{\mathrm{2}{h}}{{b}} \\ $$$$\frac{\mathrm{2}\left(\frac{{a}}{{b}}\right)−\mathrm{1}}{\lambda}=\frac{\mathrm{2}\left(\lambda−\mathrm{1}\right)}{\mathrm{1}−\left(\lambda−\mathrm{1}\right)^{\mathrm{2}} } \\ $$$$\lambda=\frac{\mathrm{4}\left(\frac{{a}}{{b}}\right)}{\mathrm{2}\left(\frac{{a}}{{b}}\right)+\mathrm{1}}=\frac{\mathrm{2}{h}}{{b}} \\ $$$$\Rightarrow{h}=\frac{\mathrm{2}{ab}}{\mathrm{2}{a}+{b}}\:\:\:\checkmark \\ $$
Commented by Spillover last updated on 20/Oct/24
$${great} \\ $$
Answered by Spillover last updated on 19/Oct/24