Y=sinx+cos2xaskiitians.com0Home » Forum » Trigonometry » Cos 2 76deg + Cos 2 14deg...Abhinav AcharyaCos276deg + Cos214deg -cos76deg.cos16deg.=2 years agoAnswer This QuestionAnswers : (1)Rinkoo GuptaAskIITians Faculty80 Pointscos276+cos214-cos76cos16(1+cos152)/2+(1+cos28)/2-cos76cos16=1+1/2[cos(180-28)+cos28]-cos76cos16=1+1/2[-cos28+cos28]-cos76cos16=1-cos76cos16=1-1/2[2cos76cos16]=1-1/2[cos92+cos60]=1-1/2[cos(90+20+1/2]=1-1/2[-sin2+1/2]=1-1/4+1/2 sin2=3/4+(1/2) sin2Thanks & RegardsRinkoo GuptaAskIITians Faculty2 years agoPost Your AnswerEnter your answer here... AnswerOther Related Questions on TrigonometryRelated QuestionA+B+C=180 PROVE THAT sin2 A-sin2 B-sin2 C=-2cosAsinBsinCThanx=(Sin y-cos y)/(siny +cosy ) then siny+ cosy,................Please give me a step wise solution of question with each & every reason From 2nd eq in question...-> ax sinß / cos²ß = by cosß / sin²ß…-> tan³ß = by / ax-> tanß = (by/ax)⅓...From tanß you can take out sinß and cos ß which are respectively:::: sinß = (by)⅓ /...Faiz\t2 months ago Correction for the last step::-> [ (by)⅔ + (ax)⅔ ] ^3/2( instead of 2/3 wrongly printed ) = a² - b²....-> (by)⅔ + (ax)⅔ = ( a² - b ) ^ 2/3......Hence proved...Sorry the powers were wrongly...Faiz\t2 months agoshow that 2 sinx+ 2 cosx >2 1 -1/square root 2 2)if tana and tan b are theroots of equation x 2 +px+qthen1) sin (a+b)=-p 2)tan(a+b)=p/q-1 3)cos a+b)1-q U must know the range of sinx and cosx. similarly sinx lessthan equal to 2 and greater than equal to ½.................(1) 1/2 > = 2^cosx > = 2.............(2) remember cosx is decreasing...Vikas TU\t5 months agoif A+B=pi/2, where A,B>0, then the maimum value of sinA + sinB is equal to Hy darshini A+B=pi/2... Therefore A=pi/2 - B.. We have to max value of SinA+SinB.. Putting tha above value it comes SinA+CosB whose maximum value is 1/root 2.. Hope U like it..Suraj Singh\t3 days agoView all Questions »Complete JEE Main/Advanced Course and Test SeriesOFFERED PRICE: R 15,000View DetailsGet extra R 3,000 offUSE CODE: MOB20Ask ExpertsHave any Question? Ask ExpertsTrigonometryAttached Image :- IMG-20170113-WA... Attach Image
Vineet Kumar , 7 Years ago
Grade 12
