音标: 英 ['kəʊsaɪn] 美 ['koʊsaɪn]
1. I still don't know iodine from cosine.
我还是分不清余弦和碘[发音相近]
2. Coefficients for sine on this monitor cosine on that one.
根据这个荧幕的正弦系数 搭配另一个荧幕的余弦
3. And so the square of sine plus cosine equals one.
所以sin2 + cos = 1
4. Now that we've specified arbitrary angles, we can define their sines and cosines.
既然已经指定了钝角 我们就可以定义它们的正弦和余弦了
5. Sine 2 theta equals 2 sine theta cosine theta.
sin2θ=2sinθcosθ