P(t)=800+1000[cos754t cos36.87° + sin754t sin36.87°]
=800+1000[cos(754t-36.87°)] (by 和角公式)
=800+1000[(4/5)cos(754t+0°) + (3/5)cos(754t-90°)] (分解成兩個向量, 一角度36.87°的直角三角形邊長比是3:4:5)
=800+ 800cos754t + 600cos(754t-90°)
=800+ 800cos754t + 600sin754t
=800+ 800cosωt + 600sinωt ,其中ω為角速度