Question

If e^–x + e^–y = 2, then `dy/dx` is ______.

Options

• e^{x – y} 

• e^{y – x}

• –e^{x – y} 

• –e^{y – x} 

Answer 1

If e^–x + e^–y = 2, then `dy/dx` is –e^{y – x}.

Explanation:

`d/dx(e^-x)+d/dx(e^-y)=d/dx(2)`

–e^–x – e^–y `dy/dx` = 0

–e^–y `dy/dx` = e^–x

`dy/dx=-e^-x/e^-y`

`dy/dx=-e^(y-x)`