sinx+cosx=1/2,nilai tan 2x=

sin x + cos x = 1/2
(sin x + cos x)² = (1/2)²
1 + sin 2x = 1/4
sin 2x = 1/4 - 1
sin 2x = -3/4

cos² 2x = 1 - sin² 2x
cos 2x = 1/4 √7

tan 2x = sin 2x / cos 2x = -3/√7 = -3/7 √7