英语周报答案网2018-2022牛津

Dear Tomam excited to tell you that the first Science and Technology Festival was held in ourschool last month, which aimed at enriching us students' school life and promoting thestudents' awareness of innovationThere were a variety of activities in the festival, which included Makers onCampus, where participants could show their designs and products, and an exhibition ofthe students' original inventions, designs and literary works. With the enthusiasticparticipation and support of all the students, the activity turned out a great success. I wasastonished at the schoolmates'creativity and teamwork spiritsi do hope more activities will be held in my school to provide us with chances to practiceour critical thinking and problemsolving abilitiesYoursLi hua

10.解:(1)因为f(x)=a·2+2-的定义域为R,且为奇函数,所以f(0)=0,所以a=-1,当a=-1时,f(x)=2--2,f(-x)=2-2-=f(r)所以函数f(x)为奇函数故实数a的值为-1.(6分)(2)44+4--kf(x)<0在区间[1,2]上恒成立,所以44+4-一k(2--2)<0,即(2--2)2+2一k(2--2)<0在区间[1,2]上恒成立,(10分)设t=2--2易知t=2--2在区间[1,2]上单调递减,则∈[-1.-](12分)则太 <已2一计+号在区间[-1-号】]上恒成(15分)所以k<(t+令g(1)=t+则g()在区间[1一2]上单两递增,g(-15)=-257所以k<_25760故实数k的取值范围为(-∞o257(20分)< p>

以上就是英语周报答案网2018-2022牛津，更多英语周报答案请关注本网站。