How to prove that #sin (pi/2 - theta)# = #cos theta# ?
1 Answer
Mar 13, 2016
see explanation
Explanation:
using appropriate
#color(blue)" Addition formula " #
#• sin(A ± B) = sinAcosB ± cosAsinB # hence
# sin(pi/2 -theta) = sin(pi/2) costheta - cos(pi/2)sintheta # now
# sin(pi/2) = 1 " and " cos(pi/2) = 0 # hence
# sin(pi/2)costheta - cos(pi/2)sintheta = costheta - 0 #
#rArr sin(pi/2 - theta ) = costheta #
