of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of tnetwork protection facilities
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
of rural drinking water sources, protection of drinking water sources in rural areas by the end of the delimitation of the scope of protection, complete with warning signs, isolating network protection facilities
17.已知抛物线过(0,y1)、(3,y2),若y1> y2, 那么a的取值范围是▲;
18.已知在△ABC中,∠C=90o,AC=3,BC=4.在平面内将△ABC绕B点旋转,点A落到A’ ,点C落
到C’ ,若旋转后点C的对应点C’和点A、点B正好在同一直线上,那么∠A’ AC’的正切值等于▲;
三、解答题:(本大题共7题,满分78分)
19.(本题满分10分)
计算:
20.(本题满分10分,第(1)小题满分7分,第(2)小题满分3分)
一个弓形桥洞截面示意图如图所示,圆心为O,弦AB是水底线,OC⊥AB,AB=24m,
E
D
C
O
B
A
sin∠COB=,DE是水位线,DE∥AB。
(1)当水位线DE=m时,求此时的水深;
(2)若水位线以一定的速度下降,当水深8 m时,
求此时∠ACD的余切值。
第20题图
21.(本题满分10分,每小题满分各5分)
第21题图
A
D
E
C
B
如图,在△ABC中,AB=AC=12,DC=4,过点C作CE∥AB交BD的延长线于点E ,,
(1)求(用向量、的式子表示);
(2)求作向量(不要求写作法,但要指出所
作图中表示结论的向量).
22.(本题满分10分)
B
A
C
海平面
在某反潜演****中,我军舰A测得潜艇C的俯角为300,位于军舰A正上方2000米的反潜直升机B测得潜艇C的俯角为680,试根据以上数据求出潜艇C离开海平面的下潜深度。
(结果保留整数。参考数据:sin680≈,cos680≈,tan680≈, ≈)
第22题图
of rural drinking water sources, protection of drinking water sources in ru
最新2022学年奉贤区调研测试试卷及答案 来自淘豆网www.taodocs.com转载请标明出处.