14. If [tex]$x = e^t + \sin(t)$[/tex] and [tex]$y = e^t - \cos(t)$[/tex], find [tex][tex]$\frac{dy}{dx}$[/tex][/tex].

A. [tex]\frac{e^t \sin(t)}{e^t + \cos(t)}[/tex]

B. [tex]\frac{e^t - \sin(t)}{e^t + \cos(t)}[/tex]

C. [tex]\frac{e^t - \sin(t)}{e^t - \cos(t)}[/tex]

D. [tex]\frac{e^t + \cos(t)}{e^t - \sin(t)}[/tex]



Answer :

To find [tex]\(\frac{dy}{dx}\)[/tex] given [tex]\(x = e^t + \sin(t)\)[/tex] and [tex]\(y = e^t - \cos(t)\)[/tex], we can proceed as follows:

1. Compute [tex]\( \frac{dy}{dt} \)[/tex]:
Given [tex]\( y = e^t - \cos(t) \)[/tex], we differentiate [tex]\( y \)[/tex] with respect to [tex]\( t \)[/tex]:
[tex]\[ \frac{dy}{dt} = \frac{d}{dt} (e^t - \cos(t)) \][/tex]
Using the differentiation rules for [tex]\( e^t \)[/tex] and [tex]\(\cos(t)\)[/tex], we get:
[tex]\[ \frac{dy}{dt} = e^t - (-\sin(t)) = e^t + \sin(t) \][/tex]

2. Compute [tex]\( \frac{dx}{dt} \)[/tex]:
Given [tex]\( x = e^t + \sin(t) \)[/tex], we differentiate [tex]\( x \)[/tex] with respect to [tex]\( t \)[/tex]:
[tex]\[ \frac{dx}{dt} = \frac{d}{dt} (e^t + \sin(t)) \][/tex]
Using the differentiation rules for [tex]\( e^t \)[/tex] and [tex]\(\sin(t)\)[/tex], we get:
[tex]\[ \frac{dx}{dt} = e^t + \cos(t) \][/tex]

3. Form the ratio [tex]\( \frac{dy}{dx} \)[/tex]:
We use the chain rule to get [tex]\( \frac{dy}{dx} \)[/tex]:
[tex]\[ \frac{dy}{dx} = \frac{dy/dt}{dx/dt} = \frac{e^t + \sin(t)}{e^t + \cos(t)} \][/tex]

Therefore, the simplified form of [tex]\( \frac{dy}{dx} \)[/tex] is:
[tex]\[ \frac{e^t + \sin(t)}{e^t + \cos(t)} \][/tex]

Comparing this with the options provided:
[tex]\[ \boxed{\frac{e^t + \sin(t)}{e^t + \cos(t)}} \][/tex]

Hence, the correct answer is indeed:
[tex]\[ \boxed{(B) \frac{e^t + \sin(t)}{e^t + \cos(t)}} \][/tex]