Question

solve this

i got answer -1/7​

Answer 1

Solution:-

$\frac{3 \cos(55) }{7 \sin(35) } - \frac{4( \cos(70) \csc(20)) }{7( \tan(5) \tan(25) \tan(45) \tan(65) \tan(85) } \\ \\ = > \frac{3 \sin(35) }{7 \sin(35) } - \frac{4. \cos(70) .\sec(70) }{7. \tan(5). \tan(25).1. \cot(25). \cot(5) } \\ \\ = > \frac{3}{7} - \frac{4. \cos(70). \frac{1}{ \cos(70) } }{7. \tan(5) . \tan(25). \frac{1}{ \tan(25) } . \frac{1}{ \tan(5) } } \\ \\ = > \frac{3}{7} - \frac{4}{7} \\ \\ = > \frac{ - 1}{7}$

IDENTITY USED :-

☆ SinA = Cos( 90°-A)

☆ CosecA = Sec(90° -A)

☆ TanA = cot ( 90°-A)

&

☆ TanA = 1/CotA

=> TanA × CotA = 1.

☆ SecA = 1/ CosA

=> SecA × CosA = 1.

& Tan 45° = 1.

Answer 2

Hope it helps..........