cos360°=2cos²180°-1=1
cos270°=cos(360°-90°)=cos90°cos360°+sin90°sin360°=0×1+1×0=0
10cos270º+4sin0º+9tan0º+15cos360º
=10×0+4×0+9×0+15×1
=15
cos360°=2cos²180°-1=1
cos270°=cos(360°-90°)=cos90°cos360°+sin90°sin360°=0×1+1×0=0
10cos270º+4sin0º+9tan0º+15cos360º
=10×0+4×0+9×0+15×1
=15