Question

prove that cos∅-2 cos 3∅ by 2 sin 3∅-sin∅=cot∅​

Answer 1

hey mate this is your answer

(since its difficult to write theta in mobile so i ma taking theta as a)

now i am first solving LHS

(cos a-2cos³a)/(2sin³a-sin a)

(cos a(1-2cos²a))/(sin a(2sin²a-1)) taking cos and sin common

we know that sin²a-cos²a=1

cos a(1-2(1-sin²a))/sin a(2sin²a-1) on solving

cos a(2sin²a-1)/sin a(2sin²a-1) after cancelling 2sin²a-1

cos a/sin a=cot a

Hence proved LHS =RHS

if u not understood this so I had attached photo kindly go through it

Hope it helps

pls mark me brainliest