Hi i have a problem with quadratic splnes, i am supposed to find S_1 and S_2 that interpolates the following points S(-1)=0 S(0)=1 S(1)=2, and at the same time we want to find S such that  \int_{-1}^1 \! (S(x))^2 \, \mathrm{d}x. is minimal. The answer is on the form
<br />
S_1(x)=a_1 x^2 +b_1x +c_1  on [-1,0] and
 <br />
S_2(x)=a_2x^2 +b_2x +c_2 on [-1,0]

my answer:
I use the data points and find that a1=-a2, b1=b2 and c1=c2=1, but I have no idea how to use minimize <br />
\int_{-1}^1 \! (S(x))^2 \, \mathrm{d}x.<br />
, can i divide it up?

<br />
min\int_{-1}^1 \! (S(x))^2 \, \mathrm{d}x.=min (\int_{-1}^0 \! (S_1(x))^2 \, \mathrm{d}x. +\int_{0}^1 \! (S_2(x))^2 \, \mathrm{d}x. ) ?<br />
I know i should get an expression and probably set the derivative to zero but i just dont know how to attack the minimizing itegral since the functions has two parts. Help greatly appreciated.