Find the solution to the differential equation
7(du/dt)=u^2
u(0)=6
U=?
Find the solution to the differential equation
7(du/dt)=u^2
u(0)=6
U=?
@Mathematics

Question

Find the solution to the differential equation
7(du/dt)=u^2
u(0)=6
U=?
 Find the solution to the differential equation
7(du/dt)=u^2
u(0)=6
U=?
 @Mathematics

anonymous · Answer

so far i have 7/u=t

anonymous · Answer

hello?

anonymous · Answer

This is a first-order nonlinear differential equation.  Let's rewrite it as $${du \over u^2} = {1 \over 7} dt$$Integrate both sides$$-{1 \over u} = {1 \over 7} t + C_1$$ Solve for u$$u = -{7 \over t} + {1 \over C_1} = -{ 7 \over 7C_1 + t}$$ Solving for C from initial conditions. $$6 = -{7 \over 7C_1} = -C_1$$

anonymous · Answer

ok let me do it

anonymous · Answer

hey man im stuck

anonymous · Answer

wat was your answer?

anonymous · Answer

(-7/t)+6?

anonymous · Answer

$$U = {1 \over 6} - {7 \over t}$$

anonymous · Answer

You're close.

anonymous · Answer

my math program says that is wrong

anonymous · Answer

What answer does your math program give you?

anonymous · Answer

thats the thing, it does not give you the answer

anonymous · Answer

let me just post another question and if you find the reason why your other answer could be wrong just message me or somthing

anonymous · Answer

$$U = {42 \over 7 - 6t}$$ Give wolframalpha.com a try.

anonymous · Answer

http://www2.wolframalpha.com/input/?i=7%28du%2Fdt%29%3Du%5E2+and+u%280%29+%3D+6

anonymous · Answer

ya thats right thank you