If π+α is in the third or fourth quadrant, then α must be in the 1 or the second quadrant, and α=2πk+π/6 or α=2πk+5π/6, where k is an arbitrary integer. therefore

sinα= 1/2，

Cosα=+ (root number 3)/2 or-(root number 3)/2,

Tanα=sinα/cosα= positive or negative 1 divided by (root number 3)