AI Mentor

Check Your IQ

Free Expert Demo

Try Test

Courses

Dropper NEET Course Dropper JEE Course Class - 12 NEET Course Class - 12 JEE Course Class - 11 NEET Course Class - 11 JEE Course Class - 10 Foundation NEET Course Class - 10 Foundation JEE Course Class - 10 CBSE Course Class - 9 Foundation NEET Course Class - 9 Foundation JEE Course Class -9 CBSE Course Class - 8 CBSE Course Class - 7 CBSE Course Class - 6 CBSE Course

Offline Centres

Without using trigonometric tables what will be the value of $3 cos 43 ° sin 47 ° 2 − cos 37 ° cosec 53 ° tan 5 ° tan 25 ° tan 45 ° tan 65 ° tan 85 °$ ?

see full answer

Your Exam Success, Personally Taken Care Of

1:1 expert mentors customize learning to your strength and weaknesses – so you score higher in school , IIT JEE and NEET entrance exams.

An Intiative by Sri Chaitanya

answer is B.

(Unlock A.I Detailed Solution for FREE)

Best Courses for You

JEE

NEET

Foundation JEE

Foundation NEET

CBSE

Detailed Solution

Given that,

3 cos 43 ° sin 47 ° 2 − cos 37 ° c o s e c 53 ° tan 5 ° tan 25 ° tan 65 ° tan 85 °

We use,

c o s e c θ = 1 sin θ sin (90 ° − θ) = cos θ cos (90 ° − θ) = sin θ tan (90 ° − θ) = cot θ tan θ cot θ = 1

We get,

= 3 cos 43 ° sin (90 − 43) ° 2 − cos (90 − 53) ° 1 sin 53 ° tan (90 − 85) ° tan (90 − 65) ° tan 65 ° tan 85 °

= 3 cos 43 ° cos 43 ° 2 − sin 53 ° 1 sin 53 ° cot 85 ° cot 65 ° tan 65 ° tan 85 °

= 32 − 1 cot 85 ° tan 85 ° cot 65 ° tan 65 °

= 9 − 1

= 8

Thus the value of

3 cos 43 ° sin 47 ° 2 − cos 37 ° c o s e c 53 ° tan 5 ° tan 25 ° tan 65 ° tan 85 °

will be

8

.
Therefore the correct option is 2.

Watch 3-min video & get full concept clarity

courses

No courses found

Result Producing online coaching for JEE/NEET of south India

Largest All India Test Series for JEE/NEET

Best Online Course for IIT JEE

Best Online Course for NEET

Best Online Course for CBSE

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Get Expert Academic Guidance – Connect with a Counselor Today!