- #1
logan3
- 83
- 2
hi,
I could you some help with a basic problem please.
it asks to verify that x*sin(y) = cos(y) is an implicit solution to [itex]\frac{dy}{dx}[/itex] (x*cot(y) +1) = -1
Here's what I have so far:
x*sin(y) = cos (y)
[itex]\frac{dx}{dx}[/itex] * sin(y) * (([itex]\frac{d}{dx}[/itex]) * sin(y)) * ([itex]\frac{dy}{dx}[/itex]) = ([itex]\frac{d}{dx}[/itex]) cos(y) * ([itex]\frac{dy}{dx}[/itex])
[itex]\rightarrow[/itex] sin(y) * cos(y) * [itex]\frac{dy}{dx}[/itex] = -sin(y) * [itex]\frac{dy}{dx}[/itex]
I'm stuck here. For example, if I try to divide both sides by sin(y) in order to elimnate sin(y), then I can't figure out how to get to the d.e. from there:
ex. (sin(y) * cos(y) * [itex]\frac{dy}{dx}[/itex]) / sin(y) = -(sin(y) * [itex]\frac{dy}{dx}[/itex]) / sin(y)
[itex]\rightarrow[/itex] cos(y) * [itex]\frac{dy}{dx}[/itex] = - [itex]\frac{dy}{dx}[/itex]
add [itex]\frac{dy}{dx}[/itex] to both sides
[itex]\rightarrow[/itex] cos(y) * [itex]\frac{dy}{dx}[/itex] + [itex]\frac{dy}{dx}[/itex] = 0
factor
[itex]\rightarrow[/itex] [itex]\frac{dy}{dx}[/itex] * (cos(y) + 1) = 0
thanks for any help.
I could you some help with a basic problem please.
it asks to verify that x*sin(y) = cos(y) is an implicit solution to [itex]\frac{dy}{dx}[/itex] (x*cot(y) +1) = -1
Here's what I have so far:
x*sin(y) = cos (y)
[itex]\frac{dx}{dx}[/itex] * sin(y) * (([itex]\frac{d}{dx}[/itex]) * sin(y)) * ([itex]\frac{dy}{dx}[/itex]) = ([itex]\frac{d}{dx}[/itex]) cos(y) * ([itex]\frac{dy}{dx}[/itex])
[itex]\rightarrow[/itex] sin(y) * cos(y) * [itex]\frac{dy}{dx}[/itex] = -sin(y) * [itex]\frac{dy}{dx}[/itex]
I'm stuck here. For example, if I try to divide both sides by sin(y) in order to elimnate sin(y), then I can't figure out how to get to the d.e. from there:
ex. (sin(y) * cos(y) * [itex]\frac{dy}{dx}[/itex]) / sin(y) = -(sin(y) * [itex]\frac{dy}{dx}[/itex]) / sin(y)
[itex]\rightarrow[/itex] cos(y) * [itex]\frac{dy}{dx}[/itex] = - [itex]\frac{dy}{dx}[/itex]
add [itex]\frac{dy}{dx}[/itex] to both sides
[itex]\rightarrow[/itex] cos(y) * [itex]\frac{dy}{dx}[/itex] + [itex]\frac{dy}{dx}[/itex] = 0
factor
[itex]\rightarrow[/itex] [itex]\frac{dy}{dx}[/itex] * (cos(y) + 1) = 0
thanks for any help.