Question

find the equation of the curve for which y''=6x-4 and which passes through (1,2) and (-2,5).

Answer 1

y"= 6x-4
y' = 3x^2 - 4x + a
y = x^3 - 2x^2 + ax + b

y(1) = 2 and y(-2) = 5, so

1-2+a+b = 2
-8-8-2a+b = 5

a = -6, b=9, so

y = x^3 - 2x^2 - 6x + 9

Answer 2

How did you get -6 and 9, please elaborate