“SOHCAHTOA” 是一个有用的助记符，用于记住三角函数 正弦、余弦 和 正切 的定义，即，正弦等于对边比斜边，余弦等于邻边比斜边，正切等于对边比邻边。
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其他助记符包括
1. "Tommy On A Ship Of His Caught A Herring" (可能在英国比美国更常见)。
2. "Oscar Has A Hold On Angie."
3. "Oscar Had A Heap of Apples."
4. "The Old Army Colonel And His Son Often Hiccup" (这给出了函数以正切、余弦、正弦的顺序)。
5. "Studying Our Homework Can Always Help To Obtain Achievement."
6. "Some Old Hippy Caught Another Hippy Tripping On Acid."
