Question

if cos A =3/4 then sin A/2 sin 5A/2 =

Answer 1

Step-by-step explanation:

½(cos3A-cos2A)

cos3A = 4cos³A-3cosA

cos2A = 2cos²A - 1

substitute cosA in these equations and u will get the value

hope this helps

Answer 2

Step-by-step explanation:

If cos A = 3/4 then the value of 16cos² (A / 2) -32 sin (A/2) sin (5A / 2) is

(A) - 4

(B)-3