已知a,b属于（x+pai/3),sin(a+b)=-3/5,sina(b-pai/4)=12/13,则cos(a+pai/4)=?
分类：英语
The Hamiltons often forage for food with other "free economy" people in Bristol.For example the Leigh Woods near the city yield abundant berries and fruit.Friday 30 July 2010 | Retail and Consumer feed All feeds --> Advertisement PROMOTIONS Virgin Holidays:save up to 40 per cent Free Annual ReportsIn the frozen food supermarket's bay are 10 blue dumpsters.The amount of food that has been thrown out is immense.In one skip there are at least 30 sliced Kingsmill loaves,within their sell-by date and with packaging intact (0.00085pc of Mr Brown's 7m wasted daily slices).Thursday nights are the best,bulgari watches,as that is when M&S apparently bins the most grub (some of which it covers in blue dye to stop bin-divers).Trade from only 9.95 commission per trade on 17 live international markets with TD Waterhouse.Find out more."I felt that I was being paid to manipulate people [in the marketing job] and create products that didn't really exist.So I just thought 'I am going to take some breathing space'," he says.MOTORING Bentley Continental Supersports Convertible in pictures FANTASY FOOTBALL Have you got what it takes to win 50,000?ONLINE DATING Join for free and find someone amazing today CULTURE Toy Story 3:10 other great weepies for men The mattress came from Freecycle.org,a free online exchange site.All he paid for were the screws to put it together."The entire bed cost me less than ?3," he boasts.The cost of this food in the shop would be around ?25,cartier watch tank,I estimate.Back to top"Look at the papers.They are dominated by the credit crisis and the global food crisis and concerns over the environment,this is major stuff occurring," he says.As a rule,Marks & Spencer bins provide the gold standard for dumpster diving.Hot topicsThe Gianstefanis say that this is nothing - they once found a bin full of fresh,chilled Canadian lobster outside an M&S."We had a party," Mrs Gianstefani says.MORE FROM TELEGRAPH.CO.UK (C) Copyright of Telegraph Media Group Limited 2010Existing freegans say that people are joining their ranks by the week.But these are not dippy hippies or trampy hobos.They are educated people who have decided to seek an alternative way of life outside the economic norms.Mr Gianstefani says that everyone should try freegansim."We are all responsible.It would be good if Gordon Brown did some bin raiding," he says,adding that his lifestyle makes him feel "like an adventurer on a permanent camping trip".Finance Most ViewedEmail Print Share | Email | Print http://www.telegraph.co.uk/finance/newsbysector/retailandconsumer/2793564/Dumpster-diving-with-the-freegans-Why-pay-for-food.html TelegraphNews Retail and Consumer Get feed updates Finance Get feed updates Markets Get feed updates Video Review Of The Year 2008 Get feed updates RELATED PARTNERS Weather ForecastEvery month,one lucky patient wins free life-changing laser eye surgery at Optical Express.Find out more.Politics Pakistan Afghanistan Cricket BP Athletics Olympics 2012:The countdown Football Transfers News Politics World News Obituaries Travel Health Jobs Football England World Cup 2010 Live Scores Culture Motoring Dating Finance Personal Finance Economics Markets Fashion Property Games Comment Blogs My Telegraph Letters Technology Food and Drink Offers Contact Us Privacy Policy Advertising A to Z Tickets Announcements Promotions Reader Prints RSS feeds Mobile Epaper Expat Subscriber Syndication Earlier this month Prime Minister Gordon Brown complained that Britons throw out ?10bn of food each year.This includes 7m slices of bread and 4.4m apples each day.Terms and Conditions Link to this video Sleep is cheap for Dave Hamilton.That's because the Bristolian paid almost nothing for his king-sized wooden bed.Mr Hamilton salvaged the bed frame from a skip."Look at this.It still surprises me and shocks me," says Mr Gianstefani.ArchiveThe couple only take a small amount of food on this occasion,bulgari watch,leaving the vast majority for other divers.Skip to article Skip to navigation Back in Ireland,Alf agrees."More and more people are beginning to wake up.The couple's cash outlay each year is less than ?2,000 and much of that goes on van maintenance.A freegan called Alf is driving around Ireland in his camper van,which runs on waste vegetable oil,when I catch up with him.Alf,who declined to give his surname,has been a freegan since he quit his job as an account executive at a London marketing design company in 1999.Alf studied experimental psychology at New College,Oxford.He is resolutely middle-class and loves the freegan lifestyle.He and fellow freegans share resources ("apart from underwear and toothbrushes").Being a freegan is about reassessing needs,MBT shoe,bartering,sharing and clamping down on wastage,says Alf."The amount of food we find round the back of supermarkets is colossal.One time I found a whole bin bag of cider.Friends found 150 frozen chickens,steaks and cheeses."
tan（α/2）=sin（α/2） /cos（α/2）=【2sin（α/2）cos（α/2）】 /【 2(cosα/2)^2】=sinα/(1+cosα)sin（α/2） /cos（α/2）=【2sin（α/2）cos（α/2）】 /【 2(cosα/2)^2】这步到这步怎么化底= =.
已知函数fx=2cosx（sinx-cosx）+1,x∈R..1.求fx的最小正周期2.求函数fx在区间[π/8,3π/4]上的最小值最大值
（1）这样形式的题,一般都化成2x的三角函数,所以周期为πf(x)=2sinxcosx-2cosx^2+1=sin2x-cos2x=根号2/2sin(2x-π/4)(2)x∈[π/8,3π/4] （2x-π/4）∈[0,5π/4]max=根号2/2 min=-0.5 (x=3π/4时)
高中数学f(x)是定义在R上的偶函数,当x
0,即0,-1,1为答案">注意题干,原函数为f(x)cosx,题干为他的导函数,该函数先增后减又有f(-2)=0,偶函数,所以f(2)=0,所以x属于（-2,2）,f(x)>0,即0,-1,1为答案
f﹙x﹚＝﹣x?＋2x=-（x-1）?+1当x=1时 y最大为1当x=3时 y最小为-3∴A=【-3 ,1】
如何用matlab画出函数y=x*exp（-2X）的图像?用了下面的命令,但报错x=linspace(0,2.5,100); y=x*exp(-2*x）;
x=0:2.5:100;y=x.*exp(-2*x);plot(y);
已知函数f(x)=cos^4x+2√3sinxcosx-sin^4x求f(x的最小正周期！
f(x) = (cosx)^4-(sinX)^4+2√3sinxcosx= [(cosx)^2+(sinx)^2] [(cosx)^2-(sinx)^2]+√3sin2x= (cosx)^2-(sinx)^2+√3sin2x= cos2x+√3sin2x = 2sin(2x+π/6)最小正周期是π
其他相关问题cos(a+b)=3/5 sin(b-pai/4)=5/13 a,b 属于(0,pai/2) 求cos(a+pai/4)
分类：数学
cos(a+b)=3/5 sin(b-pai/4)=5/13 a,b 属于(0,pai/2)sin(a+b)=4/5 cos(b-pai/4)=12/13cos(a+pai/4)=cos[(a+b)-(b-pai/4)]=cos(a+b)cos(b-pai/4)+sin(a+b)sin(b-pai/4)=3/5*12/13+4/5*5/13=56/65
搜狗输入法中 有个特殊符号中的希腊/拉丁 里面有 还有数学啊 各是各样的符号快捷方式 同时按住Ctrl和Shift +z
已知函数f(x)=cos(2x-π/3)+(cosx+sinx)(cosx-sinx) 1、化简f(x)2、若方程f(x)=m在【-π/12,π/2】上有解,求实数m 的取值范围.
1.f(x)=1/2cos2x+√3/2sin2x+cos^2 x-sin^2 x=3/2cos2x+√3/2sin2x=√3sin(2x+π/3)2.x属于【-π/12,π/2】,所以2x+π/3属于【π/6,4π/3】,.所以f(x)在此区间上最小等于-1/2,最大等于√3.所以m大于-1/2,小于√3.
f(x)=2cos?(π/4-x)-2根号3(π/4+x)cos(π/4+x) 求f（5/12π）的值 求f（x）的单调递减区间若x属于【π/4,π/2】且不等式|f（x）-m|＜2恒成立,求实数m的取值范围|
中间漏的那个是sin吧?由倍角公式：f(x)=cos(π/2-2x)+1-√3sin(π/2+2x)由诱导公式：f(x)=sin2x-√3cos2x+1又辅助角公式：f(x)=2sin(2x-π/3)+1所以,f(5π/12)=2sin(π/2)+1=3递减区间：π/2+2kπ
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Copyright (C) 2017 Baidu已知sin(3pai/4+a)=5/13,cos(pai/4-b)=3/5,且0
分类：数学
sin(π/4+a)=5/13 cos(π/4+a)=12/13cos(π/4-b)=3/5 sin(π/4-b)=4/5cos(a+b)=cos[(π/4+a)-(π/4-b)]=cos(π/4+a)cos(π/4-b)+sin(π/4+a)sin(π/4-b)=3/5*12/13+5/13*4/5=56/65
函数f(x)=sin(x/3)cos(x/3)+根号3cos(x/3)平方,将f（x）写成Asin（wx+b）,求其图像对称中心的横坐标,若△ABC的三边abc满足b平方=ac,b所对的角为x,试求x的范围和f（x）的值域
f(x)=Sin(2x/3+π/3)+√3/2(-π/2+3kπ,√3/2）k∈ZCosB=(a^2+c^2-b^2)/2ac≥(2ac-b^2)/2ac=1/2,即B∈(0,π/3］f(x)∈［Sin（5π/9）+√3/2,√3）
1/2,-PI/3 -2PI/3 因此,函数y=cos^x-2cos^(x/2)的一个单调增区间为,-2PI/3
">设t = cos(x/2),-1 1/2时,单调递增.cos(x/2) > 1/2,-PI/3 -2PI/3 因此,函数y=cos^x-2cos^(x/2)的一个单调增区间为,-2PI/3
0,w>0,a∈〔0,2π〕）的形式（2）求g(x)的值域a∈【0，2π】 x∈[0,17π/12] f(x)改为f(t)">已知函数F(x)=根号[(1-t)/(1+t)],g(x)=cosx*f(sinx)+sinx*f(cosx)（1)将函数g(x)化简成Asin(wx+a)+B(A>0,w>0,a∈〔0,2π〕）的形式（2）求g(x)的值域a∈【0，2π】 x∈[0,17π/12] f(x)改为f(t)
0,w>0,a∈【0,2π】g(x)=2-sinx-cosx=√2sin(x-3π/4)+2（2）由-π/2 +2kπ
">（1) f(t)=√[(1-t)/(1+t)]f(sinx)=√[(1-sinx)/(1+sinx)]f(cosx)=√[(1-cosx)/(1+cosx)]g(x)=cosx*f(sinx)+sinx*f(cosx)=cosx*√[(1-sinx)/(1+sinx)]+sinx*√[(1-cosx)/(1+cosx)]=√[((cosx）^2*(1-sinx))/(1+sinx)]+√[((sinx）^2*(1-cosx))/(1+cosx)]=√[((1-(sinx)^2)*(1-sinx))/(1+sinx)]+√[((1-(cosx)^2)*(1-cosx))/(1+cosx)]=√[((1+sinx)*(1-sinx)*(1-sinx))/(1+sinx)]+√[((1+cosx)*(1-cosx)*(1-cosx))/(1+cosx)]=√[(1-sinx)^2]+√[(1-cosx)^2]=1-sinx+1-cosxA>0,w>0,a∈【0,2π】g(x)=2-sinx-cosx=√2sin(x-3π/4)+2（2）由-π/2 +2kπ
-ko赛因tan
-坦捡提ctan
-ko坦捡提log
y=-x?-2x+3对称轴是x=-1①x≤-2时没有最小值x=-2时,有最大值=-4+4+3=3②x≤2时没有最小值x=-1时,有最大值=-1+2+3=4③-2≤x≤1时x=1时,有最小值=-1-2+3=0x=-1时,有最大值=-1+2+3=4④x=3时,有最小值=-9-6+3=-12x=0时,有最大值=0-0+3=3手机提问的朋友在客户端右上角评价点【评价】,然后就可以选择【满意,问题已经完美解决】了
令F（x）=f(x)+f'(x)=cos(根3x+A)-根3*sin(根3x+A)因为他是奇函数且定义域为R,所以必有F（0）=0所以cosA-根3*sinA=0所以A=π/6一楼 求导求错了
其他相关问题在三角形ABC中,角A,B,C的对边分别为a,b,c,B=pai/3,cosA=4/5,b=根号3,sinC=?求sinC的值
分类：数学
(sinA)^2=1-(cosA)^2=9/25sinA=3/5sinC=sin(A+B)=sinAcosB+sinBcosA=（3+4根号5）/10
cos(2分之3π -α) = cos(3π /2)cosα+sin(3π /2)sinα =0-1*sinα =-sinα
看周期主要看三角函数括号内的X的系数,如本题为4x则2π除以4等于0.5π,及周期是0.5π其余三角函数都是这么算的
设AB:y=kx+m,①代入x^2-y^2/2=1②,整理得(2-k^2)x^2-2kmx-m^2-2=0,设A(x1,y1),B(x2,y2),则x1+x2=2km/(2-k^2),x1x2=-(m^2+2)/(2-k^2).由①,y1y2=(kx1+m)(kx2+m)=k^2*x1x2+km(x1+x2)+m^2,∴0=向量OA*OB=x1x2+y1y2=(1+k^2)x1x2+km(x1+x2)+m^2=[-(m^2+2)(1+k^2)+2k^2*m^2+m^2*(2-k^2)]/(2-k^2)∴m^2=2(1+k^2),∴点O到直线AB的距离d=|m|/√（1+k^2)=√2.
配方f(x)=3(x-2/3)?+c-4/30
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