Question

cos 20º.cos 40º.cos 80° = ?​

Answer 1

Answer:

cos@*cos(60-@)*cos(60+@) = 1/4cos3@

@ = 20° Here

so,

cos 20º.cos 40º.cos 80° = 1/4(cos3*20) = cos60/4 = 1/8 (Ans)

(Mark as brainlist)

Answer 2

Step-by-step explanation:

Answer:

cos@*cos(60-@)*cos(60+@) = 1/4cos3@

@ = 20° Here

so,

cos 20º.cos 40º.cos 80° = 1/4(cos3*20) = cos60/4 = 1/8 (Ans)

(Mark as brainlist)