Asked by Anonymous
If x^2 + y^2 = 100 and dy/dt = 6, find dx/dt when y = 8. (Enter your answers as a comma-separated list.)
Answers
Answered by
bobpursley
take the derivative with respect to t
2x dx/dt+2ydy/dt=0
dx/dt= -y/x dy/dt
so when y=8, find x, or x=+-sqrt(100-64)
x=+-6
dx/dt=put the values in and compute. Yes, you have two solutions, the x^2+y^2 is not a function, it does not obey simple rules. Think about it.
Your computer tutor may not be that smart.
2x dx/dt+2ydy/dt=0
dx/dt= -y/x dy/dt
so when y=8, find x, or x=+-sqrt(100-64)
x=+-6
dx/dt=put the values in and compute. Yes, you have two solutions, the x^2+y^2 is not a function, it does not obey simple rules. Think about it.
Your computer tutor may not be that smart.
Answered by
Anonymous
wqe
Answered by
Anonymous
A street light is mounted at the top of a 15-ft-tall pole. A man 6 ft tall walks away from the pole with a speed of 7 ft/s along a straight path. How fast is the tip of his shadow moving when he is 40 ft from the pole?
Answered by
Anonymous
It is wrong