Answer:
Correct options are A) , B) , C) and D)
secA=
8
17
⇒cosA=
⇒sinA=±
15
cscB=
4
5
⇒sinB=
⇒cosB=±
3
Now cos(A+B)=cosAcosB−sinAsinB
⇒cos(A+B)=
.
−(±
.±
)=±
85
36
or ±
84
∴sec(A+B)=±
,±
