Question

c) Evaluate
cot theta tan theta (90°-0) - sec (90°- 0) cosec theta + sin² 25°
+ sin² 65° + root 3 tan 6° tan 16° tan 74º tan 84°
please solve ​

Answer 1

Answer:

CotA.tan(90°-A)-sec(90°-A)coseca+(sin²35°+sin²55°) +√3(tan5°.tan15°.tan30°.tan75°.tan85°)

=cotA.cotA-cosecA.cosecA+sin²35°+sin²(90°-35°)+√3{tan5°.tan15°.(1/√3).

tan(90°-15°).tan(90°-5°)}

=cot²A-cosec²A+sin²35°+cos²35°+√3×1/√3(tan5°tan15°cot15°cot5°)

=-1+1+{tan5°tan15°(1/tan15°)(1/tan5°)}

= 1

hope this will help you