2 תשובות
מוח עזב את הצ'אט
f(x)=-x^4+4px^3
f'(x)=-4x^3+12px^2=0
4x^2(-x+3p)=0
4x^2=0
x^2=0
x=0
x+3p=0-
x=3p
f"(x)=-12x^2+24px
f"(0)=0 לא min. ולא max.
f"(3p)=-12*(3p)^2+24p(3p)=-12*9p^2+72p^2=-108p^2+72p^2=-36p^2<0
max. v
||
v
f(3p)=3
f(x)=-x^4+4px^3
f(3p)=-(3p)^4+4p(3p)^3=3
81p^4+4p*27p^3=3-
81p^4+108p^4=3-
27p^4=3
3
---- = p^4
27
1
--- = p^4
9
___
1.../
----.../ 4 = p
9......./\
f'(x)=-4x^3+12px^2=0
4x^2(-x+3p)=0
4x^2=0
x^2=0
x=0
x+3p=0-
x=3p
f"(x)=-12x^2+24px
f"(0)=0 לא min. ולא max.
f"(3p)=-12*(3p)^2+24p(3p)=-12*9p^2+72p^2=-108p^2+72p^2=-36p^2<0
max. v
||
v
f(3p)=3
f(x)=-x^4+4px^3
f(3p)=-(3p)^4+4p(3p)^3=3
81p^4+4p*27p^3=3-
81p^4+108p^4=3-
27p^4=3
3
---- = p^4
27
1
--- = p^4
9
___
1.../
----.../ 4 = p
9......./\
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