Question

Cosec39sec59-tan51cot39

Answer 1

Answer:

1

Explanation:

Cosec39sec51-tan51cot39

= cosec(90-51)sec51-tan51cot(90-51)

= sec51×sec51 - tan51× tan51

= sec²51 - tan² 51

= 1

[ Since , sec²A - tan²A = 1 ]

••••

Answer 2

$\bf\huge\textbf{\underline{\underline{According\:to\:the\:Question}}}$  

Cosec 39 sec 51 - tan 51 cot 39

= cosec(90 - 51 sec 51-  tan51 cot(90 - 51)

= sec51 × sec51 - tan51 × tan51

= sec²51 - tan² 51

Using Identity

(sec²A - tan²A = 1)

Therefore

⇒ sec²51 - tan² 51  = 1