解:如图,根据题意可得,在△ABC中,AB=99海里,∠ABC=53°,∠BAC=27°,
过点C作CD⊥AB,垂足为点D.
设BD=x海里,则AD=(99﹣x)海里,
在Rt△BCD中,tan53°=CDBD
桂林在经纬网上的位置大致是25°N、110°E,这里( )
根据短文理解,选择正确答案。
Attention, Students! Beach Party Comes!
We will hold an outdoor party in Fulong on July 10.
Activities
1). Bike riding or hiking from the Student Centre to the beach
2). A cookout (野炊) on the beach
3). Swimming and sailing competitions
You should bring
sun cream, sunglasses, hats, swimsuits, hiking shoes, and personal items
Deadline
(最后期限)
for signing up
Friday, June 28
Fee
$300 per person(每人)
Meet at the Student Centre at 9:30 am, July 10.
已知集合A={x|x2-2x<0} ,B={x|x⩽-1或x>1} ,则A∩(CRB)=( )
由Mg(OH)2和MgO组成的混合物,测得其中含镁元素的质量分数为48%.取该混合物5g,将其投入115g的稀硫酸中恰好完全反应,所得溶液中溶质的质量分数为( )