Question

Tentukan nilai berikut:
sin3π/4.sinπ/4+cos3π/4.cosπ/4

Answer 1

π = 180 derajat,
sin(3pi/4).sin(pi/4)+cos(3pi/4).cos(pi/4)
sin(3/4 180).sin(1/4 180)+cos(3/4 180).cos(1/4 180)
sin(135).sin(45)+cos(135).cos(45)
sin(180-45).sin(45)+cos(180-45).cos(45)
sin(45).sin(45) - cos(45)cos(45)
1/2 akar(2).1/2 akar(2) - 1/2 akar(2). 1/2 akar(2)
1/2 - 1/2 = 0