Tentukan nilai cos 1.110°

[tex]cos \: 1110 - 360 \\ = cos \: 750 - 360 \\ = cos \: 390 - 360 \\ = cos \: 30 = \frac{1}{2} \sqrt{3} [/tex]
atau
[tex]cos \: 1110 \\ = cos \: 1110 -( 3 \times 360) \\ = cos \: 1110 - 1080 \\ = cos \: 30 = \frac{1}{2} \sqrt{3} [/tex]