Page 125 - Bangladesh_classwiz_BOOK2018_rev_Neat

`yBwU †f±‡ii †hvMdj Kivi Rb¨ †f±i؇qi Dcv`vb¸‡jv †hvM Ki‡Z nq| Z‡e †m Rb¨ `ywU †f±i mgvb gvÎvi
n‡Z n‡e A_©vr †f±i؇qi Dcv`vb msL¨v mgvb n‡Z n‡e| ClassWiz K¨vjKz‡jU‡i mivmwi `ywU †f±‡ii †hvMdj
†ei Kiv hvq| hv wb‡Pi w¯Œ‡b †`Lv‡bv n‡jv|

†f±‡ii we‡qvM Kivi Rb¨ wØZxq †f±iwUi wecixZ †f±i cÖ_g ‡f±‡ii mv‡_ †hvM Ki‡Z nq| wKš‘ K¨vjKz‡jU‡i
mivmwi `ywU †f±‡ii we‡qvMdj †ei Kiv hvq| I †f±i `ywUi we‡qvM wb‡P †`Lv‡bv n‡jv-

11.4 ‡f±‡ii WU ¸Yb

‡f±‡ii WU ¸Yb‡K A‡bK mgq †¯‹jvi ¸YbI ejv n‡q _v‡K †Kbbv `ywU †f±‡ii WU¸Yb memgq GKwU †¯‹jvi
ivwk nq| `yBwU †f±‡ii WU ¸Yb‡K wb‡¤œvv³fv‡e cÖKvk Kiv nq-

. = | | | |

‡hLv‡b n‡jv †f±i؇qi ga¨eZ©x †KvY| `ywU †f±‡ii WU¸Yb Kivi Rb¨ †f±i `ywUi mswkøó Dcv`vb¸‡jv‡K ¸Y

K‡i ¸Ydj¸‡jv †hvM Ki‡Z nq| CASIO ClassWiz K¨vjKz‡jU‡i WU ¸Yb Kivi Rb¨ Dot Product bv‡g
GKwU we‡kl wb‡`©kbv i‡q‡Q| hv Tmenu e¨envi K‡i †ei Kiv hvq| D`vniY¯^iƒc, aiv hvK, `ywU †f±i
̂
̂
= 3 ̂ − 7 ̂ + 3 I = 5 ̂ + 3 ̂ + 2 †f±i `ywUi WU ¸Yb Kivi Rb¨ cÖ_‡g †f±i؇qi mvwi †f±i
3 5
= [−7] I = [3] K¨vjKz‡jU‡i I †f±i wn‡m‡e cÖ‡ek Kiv‡Z n‡e| Gici T menu Gi
3 2
wØZxq w¯Œb †_‡K 2 †P‡c Dot Product wbe©vPb Ki‡Z n‡e| Gici Vct B wbe©vPb K‡i = Pvc‡j
†f±i؇qi WU¸Y†bi gvb cvIqv hv‡e| hv wb‡P †`Lv‡bv n‡jv-

jÿYxq†h, . Gi cÖvß gvb k~b¨| hv wb‡`©k Ki‡Q †h †f±i `ywU ci¯úi j¤^| KviY

. = = 0

= 90°

120