Given: y' = 4x^(-2) + 2x^(-1) - 3
and y(1) = 6
Find: y
Take the integral of both sides.
Integral [ y' ] = Integral [ 4x^(-2) + 2x^(-1) - 3 ]
y = Integral [ 4x^(-2) + 2x^(-1) - 3 ]
y = (-4)x^(-1) + 2*ln|x| - 3x + C
y = -4/x + 2*ln|x| - 3x + C
Using (x,y) = (1,6)
6 = -4/1 + 2*ln|1| - 3(1) + C
6 = -4 + 0 - 3 + C
6 = -7 + C
13 = C
Therefore:
y = -4/x + 2*ln|x| - 3x + C
y = -4/x + 2*ln|x| - 3x + 13