#LyX 2.3 created this file. For more info see http://www.lyx.org/ \lyxformat 544 \begin_document \begin_header \save_transient_properties true \origin unavailable \textclass article \use_default_options true \maintain_unincluded_children false \language french \language_package default \inputencoding auto \fontencoding global \font_roman "default" "default" \font_sans "default" "default" \font_typewriter "default" "default" \font_math "auto" "auto" \font_default_family default \use_non_tex_fonts false \font_sc false \font_osf false \font_sf_scale 100 100 \font_tt_scale 100 100 \use_microtype false \use_dash_ligatures true \graphics default \default_output_format default \output_sync 0 \bibtex_command default \index_command default \paperfontsize default \spacing single \use_hyperref false \papersize default \use_geometry true \use_package amsmath 1 \use_package amssymb 1 \use_package cancel 1 \use_package esint 1 \use_package mathdots 1 \use_package mathtools 1 \use_package mhchem 1 \use_package stackrel 1 \use_package stmaryrd 1 \use_package undertilde 1 \cite_engine basic \cite_engine_type default \biblio_style plain \use_bibtopic false \use_indices false \paperorientation portrait \suppress_date false \justification true \use_refstyle 1 \use_minted 0 \index Index \shortcut idx \color #008000 \end_index \leftmargin 5mm \topmargin 2cm \rightmargin 5mm \bottommargin 5mm \secnumdepth 3 \tocdepth 3 \paragraph_separation indent \paragraph_indentation default \is_math_indent 0 \math_numbering_side default \quotes_style french \dynamic_quotes 0 \papercolumns 1 \papersides 1 \paperpagestyle empty \tracking_changes false \output_changes false \html_math_output 0 \html_css_as_file 0 \html_be_strict false \end_header \begin_body \begin_layout Standard \begin_inset ERT status open \begin_layout Plain Layout \backslash null \end_layout \end_inset \end_layout \begin_layout Standard \begin_inset VSpace vfill \end_inset \end_layout \begin_layout Standard \begin_inset Box Boxed position "t" hor_pos "c" has_inner_box 1 inner_pos "t" use_parbox 0 use_makebox 0 width "65col%" special "none" height "1in" height_special "totalheight" thickness "0.4pt" separation "3pt" shadowsize "4pt" framecolor "black" backgroundcolor "none" status open \begin_layout Plain Layout \begin_inset VSpace 1cm \end_inset \end_layout \begin_layout Plain Layout Soit la suite \begin_inset Formula $u$ \end_inset telle que \begin_inset Formula $u_{0}=2$ \end_inset et \begin_inset Formula $u_{n+1}=5u_{n}+4$ \end_inset pour tout entier \begin_inset Formula $n\geqslant1$ \end_inset , et soit \begin_inset Formula $v$ \end_inset la suite définie par \begin_inset Formula $v_{n}=u_{n}+1$ \end_inset pour tout entier \begin_inset Formula $n\geqslant1$ \end_inset . \end_layout \begin_layout Plain Layout Montrer que la suite \begin_inset Formula $v$ \end_inset est une suite géométrique dont on donnera la raison et le premier terme puis donner une formule pour \begin_inset Formula $v_{n}$ \end_inset puis pour \begin_inset Formula $u_{n}$ \end_inset en fonction de l'entier naturel \begin_inset Formula $n$ \end_inset . \end_layout \begin_layout Plain Layout \begin_inset VSpace 1cm \end_inset \end_layout \begin_layout Plain Layout \begin_inset ERT status open \begin_layout Plain Layout \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \end_layout \end_inset \end_layout \end_inset \end_layout \begin_layout Standard \begin_inset VSpace 1cm \end_inset \begin_inset Box Boxed position "t" hor_pos "c" has_inner_box 1 inner_pos "t" use_parbox 0 use_makebox 0 width "100col%" special "none" height "1in" height_special "totalheight" thickness "0.4pt" separation "3pt" shadowsize "4pt" framecolor "black" backgroundcolor "none" status open \begin_layout Plain Layout \begin_inset VSpace 1cm \end_inset \end_layout \begin_layout Plain Layout Établir, en faisant apparaitre les calculs, le tableau de signe sur \begin_inset Formula $\mathbb{R}$ \end_inset de la fonction \begin_inset Formula $f:x\mapsto3x^{2}+4x-7$ \end_inset et en déduire les solutions sur \begin_inset Formula $\mathbb{R}$ \end_inset de l'inéquation \begin_inset Formula $3x^{2}+4x+8\leqslant15$ \end_inset . \end_layout \begin_layout Plain Layout (Si vous ne parvenez pas à le faire par le calcul, une résolution graphique du problème rapportera une partie des points) \end_layout \begin_layout Plain Layout \begin_inset VSpace 1cm \end_inset \end_layout \begin_layout Plain Layout \begin_inset ERT status open \begin_layout Plain Layout \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \backslash hrule \backslash vspace{8mm} \end_layout \end_inset \end_layout \end_inset \end_layout \end_body \end_document