Diff Equation ???????

Find y such that it passes from (0,3)

dy/dx-2y/(x+1)=(x+1)3

8 Answers

33
Abhishek Priyam ·

y=((x+1)4/2)+5/2

y=((x+1)4/2)+(5/2)(x+1)2

1
skygirl ·

second one is correct........i think.....
i also got dat......

33
Abhishek Priyam ·

y'=2(x+1)3

y'-2y/(x+1)=(x+1)3 (given eqn)

y'=2(x+1)3-2y/(x+1)=

My mistake............
Opsie got it...........

1
skygirl ·

its a simple linear diff eqn..

int factor = e∫(-2/(x+1))dx =(x+1)-2

so multiplying on both sides n doing all those traditional works...
finally,

∫d[y/(x+1)2] = ∫(x+1)dx
=> [y/(x+1)2] = x2/2 +x +k

given f(0)=3...
so,

3/1 = 0 +0 + k
=> k=3

hence the function is [y/(x+1)2] = x2/2 +x +3

simplifying we get.......

y=((x+1)4/2)+(5/2)(x+1)2

33
Abhishek Priyam ·

Ok got my mistake.....

33
Abhishek Priyam ·

cos(x+y)dy=dx

62
Lokesh Verma ·

(x+y)=t

1+dy/dx=dt/dx

cost (dt/dx-1)=1

dt/dx=1+1/cost

33
Abhishek Priyam ·

Ok..........

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