• Sep 21st 2010, 02:54 PM
jgv115
I've got a basic understand of differentiation and working the equation of the tangent on a point of a parabola etc

I don't know how to do this question though:

For the curve \$\displaystyle y=ax^2+bx+c \$, where a,b and c are constants, it is given that at the points (2,12) and (-1,0) the slope of the tangent is 7 and 1 respectively. Find a, b and c.

How do I go about starting this question??
• Sep 21st 2010, 02:58 PM
skeeter
Quote:

Originally Posted by jgv115
I've got a basic understand of differentiation and working the equation of the tangent on a point of a parabola etc

I don't know how to do this question though:

For the curve \$\displaystyle y=ax^2+bx+c \$, where a,b and c are constants, it is given that at the points (2,12) and (-1,0) the slope of the tangent is 7 and 1 respectively. Find a, b and c.

How do I go about starting this question??

you are given that y(2) = 12 , y(-1) = 0 , y'(2) = 7, and y'(-1) = 1

If y(x) = ax^2 + bx + c , then y'(x) = 2ax + b

set up some equations in terms of a, b, and c and solve.