Question

判断正误:

(tanA-sinA)2+(1-cosA)2 ＝ (secA-1)2

(　　)

Answer 1

答案：T
解析：

证明: 左式 ＝ (tanA-tanAcosA)2+(1-cosA)2            ＝ tan2A(1-cosA)2+(1-cosA)2            ＝ (tan2A+1)(1-cosA)2            ＝ sec2A(1-cosA)2            ＝ (secA-1)2 ＝ 右式.