Mtg 20: Wed, 16 Feb 11
page20-3
R o l l e ′ s t h e o r e m ⇒ ∀ ξ 2 ∈ ] 0 , ξ 1 [ s t G ( 2 ) ( ξ 2 ) = 0 ( 1 ) {\displaystyle Rolle'stheorem\Rightarrow \ \forall \xi _{2}\in ]0,\xi _{1}[st\ \ G^{(2)}(\xi _{2})=0\ {\color {red}(1)}}
A g a i n , G ( 2 ) ( 0 ) = ( 2 ) 0 H W ∗ 4.3 {\displaystyle Again,\ G^{(2)}(0){\overset {\color {red}(2)}{=}}0\ {\color {blue}HW^{*}4.3}}
( 1 ) a n d ( 2 ) R o l l e ′ s t h e o r e m ⇒ ∀ ξ 3 ∈ ] 0 , ξ 2 [ G ( 2 ) ( ξ 2 ) = 0 s t G ( 3 ) ( ξ 3 ) = ( 2 ) 0 {\displaystyle {\color {red}(1)\ and\ (2)}\ Rolle'stheorem\ \Rightarrow \ \forall \xi _{3}\in ]0,\xi _{2}[\ G^{(2)}(\xi _{2})=0\ st\ \ G^{(3)}(\xi _{3}){\overset {\color {red}(2)}{=}}0}
( 1 ) p .19 − 1 : G ( 3 ) ( t ) e ( 4 ) ( 3 ) ( t ) − t 2 ⏟ ( ξ ) ( 4 ) ( 3 ) e ( 1 ) {\displaystyle {\color {red}(1)}{\color {blue}p.19-1:}\ G^{(3)}(t){\overset {\color {red}(4)}{e}}^{(3)}(t)-{\color {red}{\underset {(\xi )(4)(3)}{\underbrace {\color {black}t^{2}} }}}e(1)}
e ( 3 ) ( t ) = H W ∗ 4.4 − t 3 [ F ( 3 ) ( t ) − F ( 3 ) ( − t ) ] ( 5 ) {\displaystyle e^{(3)}(t){\underset {\color {blue}HW^{*}4.4}{=}}-{\frac {t}{3}}[F^{(3)}(t)-F^{(3)}(-t)]\ {\color {red}(5)}}
G ( 3 ) ( ξ 3 ) = − ξ 3 3 [ F ( 3 ) ( ξ 3 ) − F ( 3 ) ( − ξ 3 ) ] ⏞ A p p l y D M V T − 60 ( ξ 3 ) 2 e ( 1 ) = ( 6 ) f r o m ( 3 ) 0 {\displaystyle G^{(3)}(\xi _{3})=-{\frac {\xi _{3}}{3}}{\color {green}{\overset {Apply\ DMVT}{\overbrace {\color {black}[F^{(3)}(\xi _{3})-F^{(3)}(-\xi _{3})]} }}}-60(\xi _{3})^{2}e(1){\underset {{\color {blue}from}{\color {red}(3)}}{\overset {\color {red}(6)}{=}}}0}
= D M V T ( f ) − ξ 3 3 [ 2 ξ 3 ⏟ ξ 3 − ( − ξ 3 ) F ( 4 ) ( ξ 4 ) ] − 60 ( ξ 3 ) 2 e ( 1 ) ξ 4 ∈ ] − ξ 3 , ξ 3 [ {\displaystyle {\underset {\color {red}(f)}{\overset {\color {blue}DMVT}{=}}}-{\frac {\xi _{3}}{3}}[{\color {blue}{\underset {\xi _{3}-(-\xi _{3})}{\underbrace {\color {black}2\xi _{3}} }}}F^{(4)}(\xi _{4})]-60(\xi _{3})^{2}e(1)\ \xi _{4}\in \ ]-\xi _{3},\xi _{3}[}