Page 106 - Bangladesh_classwiz_BOOK2018_rev_Neat

9.5 Solver e¨envi K‡i w·KvYwgwZK mgxKi‡Yi mgvavb wbY©q

Qr e¨envi K‡i ‡Kv‡bv w·KvYwgwZK mgxKiY‡K K¨vjKz‡jU‡i UvBc Ki‡Z n‡e| Gici qr
(Sovle) Pvc‡j K¨vjKz‡jUi Gi GKwU gvb PvB‡e| †h‡Kv‡bv GKwU gvb cÖ‡ek Kwi‡q =evUb Pvc‡j
mgxKi‡Yi mgvavb K¨vjKz‡jU‡i cÖ`wk©Z n‡e|

− 1−√3
D`vniY¯^iƒc, aiv hvK, = mgxKi‡Y Gi gvb †ei Ki‡Z n‡e| Gi Rb¨ K¨vjKz‡jU‡i
+ 1+√3
mgxKiYwU wb‡Pi cÖ_g w¯Œ‡bi g‡Zv UvBc Kiv‡Z n‡e| Gici qr evUb Pvc‡j K¨vjKz‡jUi Gi Rb¨ GKwU
gvb PvB‡e| Gi Rb¨ 45 cÖ‡ek Kwi‡q = evUb Pvc‡j wb‡Pi Z…Zxq w¯Œ‡bi g‡Zv djvdj cÖ`wk©Z n‡e|

9.6 wecixZ w·KvYwgwZK dvskb

dvskb‡K = Øviv msÁvwqZ Kiv n‡j, −1 = A_©vr †K w·KvYwgwZK dvskb
2
2
ejv n‡j −1 †K wecixZ w·KvYwgwZK dvskb ejv nq| hw`I Gi cwie‡Z© ( ) e¨envi Kiv
−1
−1
−1
hvq wKš‘ −1 Gi cwie‡Z© ( ) ev 1 ‡jLv hv‡e bv| , −1 I Gi cwie‡Z©

′
′
h_vµ‡g ′ , ′ ,′ ′ BZ¨vw` e¨envi Kiv hvq|
wecixZ w·KvYwgwZK dvsk‡bi ÿz`ªZg msL¨vm~PK gvb‡K (abvZ¥K ev FYvZ¥K) Gi g~L¨gvb ejv nq| myZivs

1

−1
−1
( ) Ges tan (−1) dvsk‡bi g~L¨gvb n‡jv h_vµ‡g Ges − . hLb ‡Kv‡bv wecixZ w·KvYwgwZK
2 6 4
dvsk‡bi Rb¨ `yBwU gvb nq (GKwU ÿz`ªZg msL¨vm~PK I FYvZ¥K Ges AciwU ÿz`ªZg msL¨vm~PK I abvZ¥K), ZLb
abvZ¥K gvb‡K H dvsk‡bi g~L¨gvb aiv nq|
−1
−1
−1
wecixZ w·KvYwgwZK dvsk‡bi g~L¨gvb †ei Kivi Rb¨ ClassWiz K¨vjKz‡jU‡i , I
i‡q‡Q †m¸‡jv h_vµ‡g qj, qk , ql †P‡c cvIqv hvq| Avi −1 , −1 I
1
1
1
−1 dvsk‡bi Rb¨ h_vµ‡g −1 ( ) , −1 ( ) I −1 ( ) e¨envi Ki‡Z n‡e|

D`vniY¯^iƒc aiv hvK, = −1 †hLv‡b < < 2 . Gi gvb †ei Kivi Rb¨ wecixZ w·KvYwgwZK
dvskb e¨envi K‡iI Kiv hvq| Avevi Solve e¨envi K‡iI Kiv hvq|
wecixZ w·KvYwgwZK dvskb e¨envi K‡i Gi gvb †ei Kivi Rb¨ mgxKiYwUi Abyiƒc mgxKiY wb‡Pi g‡Zv K‡i
†ei Ki‡Z n‡e|

= −1
1
−1
∴ = cot (−1),= −1 ( ) = −1 (−1)
−1
Gici CalssWiz K¨vjKz‡jU‡i ql evUb e¨envi K‡i Gi gvb cvIqv hvq hv wb‡P †`Lv‡bv n‡jv|

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