a) F(x) = x^4/4 +5/2*x^2 +C
[x^4/4+ 5/2*x^2] von -2 bis k = k^4/4 +5/2*k^2 - ((-2)^4/4 + 5/2*(-2)^2) -0 = 0
k^4/4 +5/2*k^2 = 16/4+20/2 = 14
k^4+10k^2-56 = 0
substituieren: k^2= z
z^2+10z-56 = 0
pq- Formel:
z1/2 = -5+-√(25+56) = -5+-9
z1= 4
z2= -14
-> k1= +-2
k2 = +- √-14 (entfällt)