问题
选择题
cot(
|
答案
cot(
+π 4
)+tanαα 2
=
+tanα1+cos(α+
)π 2 sin(α+
)π 2
=
+1-sinα cosα sinα cosα
=1 cosα
=secα
故选A
cot(
|
cot(
+π 4
)+tanαα 2
=
+tanα1+cos(α+
)π 2 sin(α+
)π 2
=
+1-sinα cosα sinα cosα
=1 cosα
=secα
故选A