题目
求值:sin
+cos(−
)
26π |
3 |
17π |
4 |
提问时间:2020-07-18
答案
∵sin
+cos(-
)
=sin(9π-
)+cos(4π+
)
=-sin(π+
)+cos
=sin
+cos
=
26π |
3 |
17π |
4 |
=sin(9π-
π |
3 |
π |
4 |
=-sin(π+
π |
3 |
π |
4 |
=sin
π |
3 |
π |
4 |
=
26π |
3 |
17π |
4 |
提问时间:2020-07-18
26π |
3 |
17π |
4 |
π |
3 |
π |
4 |
π |
3 |
π |
4 |
π |
3 |
π |
4 |