论文部分内容阅读
苏教版必修4第99页上有这样一道习题:“求证:sin(α+β)sin(α-β)=sin2α-sin2β”.这个公式形式优美,与平方差公式(a+b)(a-b)=a2-b2的结构十分相似,体现了数学的形
There is an exercise like this on page 99 of the Supremacy of the Supremacy: “Proof: sin (α + β) sin (α-β) = sin2α-sin2β” ) (ab) = a2-b2 is very similar in structure, reflecting the mathematical shape