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下列说法中,正确的是A.πa2的系数是B.在(-1),cot30°,,|-π-1|几个数中...
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下列说法中,正确的是( )
A.
![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAjCAYAAACdHYpiAAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAC5SURBVEhL7ZXrDYQgEIS3su2JdrYZStlS5lxQ
HpqTh8nljJoQfzEww8dAuPjRxfn4oYAKmBii9Z77duAdiGgZswJhUQ/3Ctw6gwCRcRCH8xmmPpBO
LswfCHiXvW0e0780+8VG08JBtAjTNJsCrcK5i0AJ0i7YDgtLkbAgNpmVyiiJquvkGKcd+zzK1o3j
FvLKgYlZgSCzhslFt3eEWKOkwqAU6gyJuxwGd6AQHj2F9Cod2+hRl+mkFD57HzDcVfTzBgAAAABJ
RU5ErkJggg==
)
πa
2的系数是
![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAjCAYAAACdHYpiAAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAC5SURBVEhL7ZXrDYQgEIS3su2JdrYZStlS5lxQ
HpqTh8nljJoQfzEww8dAuPjRxfn4oYAKmBii9Z77duAdiGgZswJhUQ/3Ctw6gwCRcRCH8xmmPpBO
LswfCHiXvW0e0780+8VG08JBtAjTNJsCrcK5i0AJ0i7YDgtLkbAgNpmVyiiJquvkGKcd+zzK1o3j
FvLKgYlZgSCzhslFt3eEWKOkwqAU6gyJuxwGd6AQHj2F9Cod2+hRl+mkFD57HzDcVfTzBgAAAABJ
RU5ErkJggg==
)
B.在(-1),cot30°,
![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAjCAYAAACpZEt+AAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAACOSURBVDhP3ZLRDcAgCAWZjJ1ch2UchVFesaZV
0NYf04+aEBNzeeoBYbFoI6ACJoaoz6xX5AQisnoCKoX0c+CUVDzUSrnJ2tmLh7aur7geNttL6Dph
z0Tl1CRFWQSzKJ05QCHcJssAtaNuFe0s99nwCxUGd5MbAB8/egjxAxDjAzDGe2AS74BZ/JfNemv5
Aarn9bMuq+CwAAAAAElFTkSuQmCC
)
,|-π-1|几个数中,实数有2个
C.若
![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAACkAAAAxCAYAAABH5YAAAAAAAXNSR0IArs4c6QAAAARnQU1BAACx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)
,则
![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADwAAAAxCAYAAACGYsqsAAAAAXNSR0IArs4c6QAAAARnQU1BAACx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)
D.单项式-x
n+1y与单项式2x
2n+3y不可能是同类项
相关试题
-
下列说法中,正确的是( )
A.
πa2的系数是![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAjCAYAAACdHYpiAAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAC5SURBVEhL7ZXrDYQgEIS3su2JdrYZStlS5lxQ
HpqTh8nljJoQfzEww8dAuPjRxfn4oYAKmBii9Z77duAdiGgZswJhUQ/3Ctw6gwCRcRCH8xmmPpBO
LswfCHiXvW0e0780+8VG08JBtAjTNJsCrcK5i0AJ0i7YDgtLkbAgNpmVyiiJquvkGKcd+zzK1o3j
FvLKgYlZgSCzhslFt3eEWKOkwqAU6gyJuxwGd6AQHj2F9Cod2+hRl+mkFD57HzDcVfTzBgAAAABJ
RU5ErkJggg==
)
B.在(-1),cot30°,
,|-π-1|几个数中,实数有2个
C.若
,则![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADwAAAAxCAYAAACGYsqsAAAAAXNSR0IArs4c6QAAAARnQU1BAACx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)
D.单项式-xn+1y与单项式2x2n+3y不可能是同类项
-
下列说法中,正确的是( )
A.
πa2的系数是![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABAAAAAjCAYAAACdHYpiAAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAC5SURBVEhL7ZXrDYQgEIS3su2JdrYZStlS5lxQ
HpqTh8nljJoQfzEww8dAuPjRxfn4oYAKmBii9Z77duAdiGgZswJhUQ/3Ctw6gwCRcRCH8xmmPpBO
LswfCHiXvW0e0780+8VG08JBtAjTNJsCrcK5i0AJ0i7YDgtLkbAgNpmVyiiJquvkGKcd+zzK1o3j
FvLKgYlZgSCzhslFt3eEWKOkwqAU6gyJuxwGd6AQHj2F9Cod2+hRl+mkFD57HzDcVfTzBgAAAABJ
RU5ErkJggg==
)
B.在(-1),cot30°,
,|-π-1|几个数中,实数有2个
C.若
,则![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAADwAAAAxCAYAAACGYsqsAAAAAXNSR0IArs4c6QAAAARnQU1BAACx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)
D.单项式-xn+1y与单项式2x2n+3y不可能是同类项
-
下列各式中正确的个数是( )
①
②tan60°=cot30°③
④
.
A.4
B.3
C.2
D.1
-
在-7,cot45°,sin60°,
这六个实数中,有理数的个数有( )
A.1个
B.2个
C.3个
D.4个
-
化简:
(1)
cot260°+sin30°+tan36°-4tan45°cos45°-cot54°
(2)![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAIgAAAAlCAYAAACZOKFiAAAAAXNSR0IArs4c6QAAAARnQU1BAACx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)
(3)已知关于x的方程
,
①k为何值时,方程有两个实数根?
②若方程的两个实数根x1,x2满足|x1|=x2,则k为何值?
-
下列等式中正确的是( )
A.cos2α+sin2α=1
B.cos30°+cos45°=cos75°
C.tan30°-tan60°=![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABcAAAAkCAYAAABixKGjAAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAFMSURBVEhL7ZZBsoMgDIZzLhccxz03ce1B3HKQ
LjhKmkSxCSqSmbrom/fNWBXxa/i1UEAnANC1SV/5dFBu7OHX5SnuWUFM0nTFQd64FzDPGEojH1On
MOf1/AQrTxh3IR3TNe2HnBJqVZ4DQphNm8bIczb9Uqzk2/4DD7NXrpCiDrFUcKf+WJiMc7jK3EC5
Napmrio/e16mZ4qR9IplXCuCcWtoyIk6mr0nX6hGhcuyyH4aAIfpJcctuTyvg5waTc50br5IRrBW
fy3n7ANqDchQZOh6q+IhRmrn6rXc3mvFTGOMltc0IAyTkd/R35Pg6h+TM4/KPVAh5YF8dxO5fD7E
X5dvk5LkWc8RDTrkeqY8rjYt7uU3q00LX+bVrHdHt5wrfiBzRce/A41PTsg0e7MUFtxyT+5O+brS
f+9t4UrLD8jxjjP+WBz8y09AfAOrIKTaaVtUUgAAAABJRU5ErkJggg==
)
D.2cot22°30′=cot45°=1
-
(2002•兰州)下列各式中,不正确的是( )
A.cos30°=![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAjCAYAAACpZEt+AAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAACfSURBVDhP3VNBDsAgCOvL+BPf4TM8hacwmZnD
uc2L2WEmxphgi22BTxYWFpg4gVysx6wUyg6g7KeCWuX884JdpNChbtZTrJVePNg6pzgauzsDdI6w
KFEtMEUoEs+hgoeKTboITSlKUsJUuxcm1KGMvwi6jHD9hfKbWV0/9WmiMBfiku27udhHY5yJhhCd
55DEIB13RFOjUSfVZ2a9eL4BYBXpBOX9qe0AAAAASUVORK5CYII=
)
B.sin30°=![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAjCAYAAACpZEt+AAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAACfSURBVDhP3VNBDsAgCOvL+BPf4TM8hacwmZnD
uc2L2WEmxphgi22BTxYWFpg4gVysx6wUyg6g7KeCWuX884JdpNChbtZTrJVePNg6pzgauzsDdI6w
KFEtMEUoEs+hgoeKTboITSlKUsJUuxcm1KGMvwi6jHD9hfKbWV0/9WmiMBfiku27udhHY5yJhhCd
55DEIB13RFOjUSfVZ2a9eL4BYBXpBOX9qe0AAAAASUVORK5CYII=
)
C.tan60°=![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA8AAAASCAYAAACEnoQPAAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAC0SURBVDhPzZNNDsAQEIXnXBaOY+8m1g5i6yBd
zFFe/bY0pGpViUTEN+/NA2EwiAhLcwaP9p979HOYLWTNQfvL7IJtDy0tOCFhHYpU/h1mLmAW9PoL
3CbqNeib7Vsx3f0OnEqU4KTNCbz3/HgIbCWoBEhwqjxFdV9BsDcdTd/knEvnjCAIc2Q7U5hh5Sjt
5CCrd3BUaj5Kk1ffswqHovpcuW+ma+4wAiTMHhzrRvUt5WpqFT4BvDKYovKwNAUAAAAASUVORK5C
YII=
)
D.cot45°=1
-
(2002•兰州)下列各式中,不正确的是( )
A.cos30°=![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAjCAYAAACpZEt+AAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAACfSURBVDhP3VNBDsAgCOvL+BPf4TM8hacwmZnD
uc2L2WEmxphgi22BTxYWFpg4gVysx6wUyg6g7KeCWuX884JdpNChbtZTrJVePNg6pzgauzsDdI6w
KFEtMEUoEs+hgoeKTboITSlKUsJUuxcm1KGMvwi6jHD9hfKbWV0/9WmiMBfiku27udhHY5yJhhCd
55DEIB13RFOjUSfVZ2a9eL4BYBXpBOX9qe0AAAAASUVORK5CYII=
)
B.sin30°=![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAjCAYAAACpZEt+AAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAACfSURBVDhP3VNBDsAgCOvL+BPf4TM8hacwmZnD
uc2L2WEmxphgi22BTxYWFpg4gVysx6wUyg6g7KeCWuX884JdpNChbtZTrJVePNg6pzgauzsDdI6w
KFEtMEUoEs+hgoeKTboITSlKUsJUuxcm1KGMvwi6jHD9hfKbWV0/9WmiMBfiku27udhHY5yJhhCd
55DEIB13RFOjUSfVZ2a9eL4BYBXpBOX9qe0AAAAASUVORK5CYII=
)
C.tan60°=![](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAA8AAAASCAYAAACEnoQPAAAAAXNSR0IArs4c6QAAAARnQU1BAACx
jwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAC0SURBVDhPzZNNDsAQEIXnXBaOY+8m1g5i6yBd
zFFe/bY0pGpViUTEN+/NA2EwiAhLcwaP9p979HOYLWTNQfvL7IJtDy0tOCFhHYpU/h1mLmAW9PoL
3CbqNeib7Vsx3f0OnEqU4KTNCbz3/HgIbCWoBEhwqjxFdV9BsDcdTd/knEvnjCAIc2Q7U5hh5Sjt
5CCrd3BUaj5Kk1ffswqHovpcuW+ma+4wAiTMHhzrRvUt5WpqFT4BvDKYovKwNAUAAAAASUVORK5C
YII=
)
D.cot45°=1
-
(2002•达州)下列各式正确的是( )
A.sin45°+sin45°=sin60°
B.tan30°•sin30°=cot30°
C.tan260°+sin260°=tan245°
D.tan45°=
-
(2002•达州)下列各式正确的是( )
A.sin45°+sin45°=sin60°
B.tan30°•sin30°=cot30°
C.tan260°+sin260°=tan245°
D.tan45°=