Question #0d6f1

1 Answer
Dec 5, 2017

See below.

Explanation:

Sum to product identity for the given expression:

#color(red)(sinA-sinB=2cos((A+B)/2)sin((A-B)/2))#

#sin(pi/13)-sin(pi/2)=2cos((pi/13+pi/2)/2)sin((pi/13-pi/2)/2)#

#sin(pi/13)-sin(pi/2)=2cos((15pi)/52)sin((-11pi)/52)#