f(x)=e^(3x+3)+2x³
f'(x)=3(e^(3x+3))+6x²
f'(-1)=3(e^(3*(-1)+3)+6*(-1)²= 3+6=9
f(x)=x⁴/2–2x+3/2
f'(x)= 2x³–2
2x³–2=0
2x³=2
x³=1
x=1
f(1)=1⁴/2–2*1+3/2=0,5–2+1,5=2–2=0
