Page 110 - Bangladesh_classwiz_BOOK2018_rev_Neat

5. + = 1 mgxKiYwUi mgvavb wbY©q Ki‡Z n‡e hLb 0° ≤ ≤ 90°.

mgvavb- GRb¨ cÖ_‡g sin + cos = 1 mgxKiYwU K¨vjKz‡jU‡i cÖ‡ek Kiv‡Z n‡e| Ô=Õ wPý Gi Rb¨

Qr e¨envi Ki‡Z n‡e| Gi ci qr Pvc‡j Gi gvb PvB‡e| cÖ`Ë e¨ewai wfZ‡ii †h ‡Kv‡bv
gvb (GB †ÿ‡Î 60 ‡bIqv n‡q‡Q) cÖ‡ek Kwi‡q = evUb Pvc‡j Z_v Gi gvb cvIqv hv‡e 90°.

(Key log- j[)+k[)Qr1qr60==)

6. 2 + 2 3 + 2 5 + 2 7 Gi gvb wbY©q Ki‡Z n‡e|
4 4 4 4

mgvavb- cÖ_‡g K¨vjKz‡jU‡ii G wM‡q angle unit ‡K †iwWqv‡b wb‡Z n‡e| Gici ivwkwU‡K wb‡Pi
w¯Œ‡bi g‡Zv K¨vjKz‡jU‡i cÖ‡ek Kwi‡q= Pvc‡j djvdj cÖ`wk©Z n‡e|

(Key log- qw22jqKa4))d+j3qKa4$
)d+j5qKa4$)d+j7qKa$)d =)

4
7. cos = , sin = 12 Ges I DfqB m~²‡KvY n‡j tan −tan Gi gvb wbY©q Ki‡Z n‡e|
5 13 1+tan .tan
4
mgvavb- cÖ_‡g Calculate mode G cos = UvBc K‡i qr (SOLVE) ‡P‡c Gi gvb †ei
5
Ki‡Z n‡e| Gici J †P‡c cÖvß djvdj‡K ‡g‡gvwi‡Z msiÿY Ki‡Z n‡e| GKB fv‡e Gi gvb †ei Kivi
tan −tan
ci K¨vjKz‡jU‡i UvBc K‡i = evUb Pvc‡j djvdj cÖ`wk©Z nq|
1+tan .tan

(Key log-kQz)Qr4a5qr35==Jz=j
Qx)Qr12a13qr35==Jx=Cal
Qx)plQz)$1+lQx)OlQz)=)

2
2
8. 7 + 3 = 4 n‡j Gi gvb †ei Ki‡Z n‡e|
2
2
mgvavb- Calculate mode- G cÖ_‡g 7 + 3 = 4 wb‡Pi w¯Œ‡bi g‡Zv UvBc Ki‡Z n‡e|
qr Pvcvi ci Gi †h‡Kv‡bv gvb cÖ‡ek Kwi‡q =evUb Pvc‡j Gi cÖK…Z gvb cvIqv hv‡e| J

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