Tentukan nilai tan 4l240° dari kuadran 4

[tex] \tan(41420) = \tan(t + k \times 180 { }^{0} ) = \\ \tan(20 {}^{0} + 230 \times 180 {}^{0} ) = \tan(20 {}^{0} ) [/tex]
jadi nilai tan(41240) = tan 20