Maths problem, in differential equation...

[yali2012]

Help please... and if possible, explanation on differential

 

[yali2012]

Its Nov 07/P3

 

[NehaKush]

1/N dN = k(cos 0.02t) dt
then u integrate both sides..
ln N = k/O.O2 sin(O.O2) + C
Replace N=125 & t=0
ln N = 50 k sin (0.02) + ln 125

 

[NehaKush]

(ii) 50k * sin 0.6 = ln166 - ln 125
50k * sin 0.6 = ln1.328
k = 0.01

(iii) ln N = 0.502 sin (0.02t) + ln125
ln N - ln 125= 0.502SIN(0.02t)
ln (N/125) = 0.502 sin (0.02t)
N/125 = e * 0.502 sin (0.02t)
N = 125e*0.502 sin (0.02t)

least value of N : let sin (0.02t) = -1
replace
N =75.6

 

[NehaKush]

hope iv helped..

 

[yali2012]

Thank you very much, it's been vry helpful...tyyyy