Question

Simplify $\frac{cot 55\textdegree . cot 35\textdegree - 1}{cot 55\textdegree + cot 35\textdegree}$.

Answer 1

we know, cot(90° - x) = tanx 

so, cot55° = cot(90° - 35°) = tan35° 

given, (cot55°. cot35° - 1)/(cot55° + cot35°)

= (cot35° . tan35° - 1)/(tan35° + cot35°)

we know, tanx . cotx = 1 

so, tan35° . cot35° = 1 

= (1 - 1)/(tan35° + cot35°)

= 0

hence, (cot55°. cot35° - 1)/(cot55° + cot35°) = 0

Answer 2

HELLO DEAR,



we know:-
cot(90° - x) = tanx 
tanx . cotx = 1 

so, cot55° = cot(90° - 35°) = tan35° 

given, (cot55°. cot35° - 1)/(cot55° + cot35°)

= (cot35° . tan35° - 1)/(tan35° + cot35°)

so, tan35° . cot35° = 1 

= (1 - 1)/(tan35° + cot35°)

= 0



I HOPE IT'S HELP YOU DEAR,
THANKS