Question

if sec(a-20*)=cosec 4a find a

Answer 1

we know cosec (90-a)=sec a
sec(20-a)=Sec(90-4a)
on comparing
20-a=90-4a
3a=70
hence a=70/3

Answer 2

Cosec 4a=sec(90-4a)...........(1)
Sec(a-20)=sec(90-4a) (from 1)
Sec on both side get cancel
Now
a-20=90-4a
a+4a=90+20
5a=110
a=110/5
a=22