© examsiri.com
Question : 22 of 160
Marks:
+1,
-0
Solution:
Given,
sin‌A=−‌,cot‌B=−‌Now,
cos2A=1−sin‌2A‌⇒‌‌1−(−‌)2⇒1−‌=‌‌∴‌‌cos‌A=±‌But
sin‌A<0 and
A and
B are not in 4th quadrant.
So,
A in third quadrant and
B in 2nd quadrant
∴‌‌cos‌A=−‌And
cot‌A=‌=‌=‌6‌cot‌A=‌=‌Now,
tan‌B=‌=‌And,
sec2B=1+tan2B‌⇒‌‌1+(‌)2=1+‌=‌‌⇒‌‌ secB=−‌(∵B‌ in 2nd quadrant ‌)‌⇒‌‌4 secB=‌=−‌‌∴‌‌6‌cot‌A+4 secB=‌−‌‌⇒‌‌‌=−3
© examsiri.com
Go to Question: