Answer:
dy/dx = -5y - y/x
Step-by-step explanation:
In xy + 5x = 30
Differentiating xy implicitly
y + xdy/dx
Assuming u = xy
In xy = In u
Differentiating In u = 1/u = 1/xy
Differentiating 5x = 5 and differentiating a constant (30) = 0
1/xy(y + xdy/dx) + 5 = 0
(y + xdy/dx)/xy = -5
(y + xdy/dx) = -5xy
xdy/dx = -5xy - y
dy/dx = = (-5xy - y)/x
dy/dx = -5y - y/x
Answer:
Wyzant
Question
Flying against the wind, an airplane travels 4200 km in 7 hours. Flying with the wind, the same plane travels 4000 km in 4 hours. What is the rate of the plane in still air and what is the rate of the wind?
Answer · 1 vote
Let Va = the velocity of the airplane Let Vw = the velocity of the wind When flying with the wind: (Va+Vw)*(4 hours) = 4000 4Va + 4Vw = 4000 4Vw = 4000 - 4Va Vw = 1000 - Va When flying against the wind: (Va-Vw)*(7 hours) = 4200 km7Va - 7Vw = 4200 Substitute 1000-Va for Vw and solve for Va: 7Va - 7(1000-Va) = 4200 7Va -7000 + 7Va = 4200 14Va = 11200 Va = 800 km/hr Rate of wind: Vw = 1000 - Va = 1000 - 800 = 200 km/hour
More
Socratic
Question
Flying against the wind, an airplane travels 4500 in 5 hours. Flying with the wind, the same plane travels 4640 in 4 hours. What is the rate of the plane in still air and what is the rate of the wind?
Answer · 0 votes
The speed of plane in still air is 1030 km/hr and wind
Step-by-step explanation:
Answer:
102
Step-by-step explanation:
4times 7=28. 28times4=102
Answer:
x
=
40
Step-by-step explanation:
4x°=75-x° this might be wrong but I’m sure
