Question

Question 2 Show that (I) tan 48° tan 23° tan 42° tan 67° = 1 (II)cos 38° cos 52° − sin 38° sin 52° = 0

Class 10 - Math - Introduction to Trigonometry Page 189

Answer 1

Hi bhaiya Rishi Bhaiya!

here is your answer

Answer 2

Heya,

Here is the required solution:-

(i) tan 48° tan 23° tan 42° tan 67° = 1 

L.HS. 

tan 48° tan 23° tan 42° tan 67°

= cot 42° tan 42° cot 67° tan 67°

=1

∴L.H.S = R.H.S

(ii) cos 38° cos 52° − sin 38° sin 52° = 0

L.H.S

cos 38° cos 52° − sin 38° sin 52°

= cos 38° sin 38° - sin 38° cos 38°

= 0

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