I was looking at past papers for my c2 exam next week, and I was stuck on question 7 of the june 2012 ocr mei paper.
I've got the dy/dx as 4x^3/2 - 5x + c
and the equation of the line as y - 20 = 7 (x-4)
which equals y=7x-8
and my final answer as 4x^3/2 - 5x - 8
but the mark scheme says it's 4x^3/2 -5x + 8
I don't understand how it's +8??