Question Number 39457 by Raj Singh last updated on 06/Jul/18
Answered by MrW3 last updated on 06/Jul/18
$${y}={f}\left({x}\right)={b}\:{e}^{−\frac{{x}}{{a}}} \\ $$$${f}\left(\mathrm{0}\right)={b} \\ $$$${y}'={f}'\left({x}\right)=−\frac{{b}}{{a}}\:{e}^{−\frac{{x}}{{a}}} \\ $$$${f}'\left(\mathrm{0}\right)=−\frac{{b}}{{a}} \\ $$$${eqn}.\:{of}\:{line}\:{through}\:\left(\mathrm{0},{b}\right)\:{and}\:{with} \\ $$$${slope}\:{m}=−\frac{{b}}{{a}}\:{is} \\ $$$${y}−{b}=−\frac{{b}}{{a}}\left({x}−\mathrm{0}\right) \\ $$$$\Rightarrow{ay}+{bx}={ab} \\ $$
Commented by Raj Singh last updated on 06/Jul/18
$${thanks}\:{sir} \\ $$