证明 tan^2(a)+sin^2(a)=tan^2(a)sin^2(a)

解答

证明

tan^{2} (a) + sin^{2} (a) = tan^{2} (a) sin^{2} (a)

假

求解步骤

tan^{2} (a) + sin^{2} (a) = tan^{2} (a) sin^{2} (a)

两侧不相等

对于

tan^{2} (a) + sin^{2} (a) = tan^{2} (a) sin^{2} (a)

代入

a = 1

tan^{2} (1) + sin^{2} (1) = 3.13359 \dots

tan^{2} (1) + sin^{2} (1)

整理为小数形式

= 3.13359 \dots

tan^{2} (1) sin^{2} (1) = 1.71744 \dots

tan^{2} (1) sin^{2} (1)

整理为小数形式

= 1.71744 \dots

两侧不相等

\Rightarrow 假

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