Find the value of sin 75° + sin 15° = ?
cos 75° + cos 15° =?

• sin a+sin b=2sin(a+b)/2*cos(a-b)/2
  =2sin(75+15)/2*cos(75-15)/2
  =2sin 45*cos 30
  =square root (3/2)
• 9 years agoHelpfull: Yes(8) No(0)
• By using formula
  Sin c + Sin d=2sin(c+d)/2*cos (c-d)/2
  Sin 75°+ Sin 15°= 2 sin(75°+15°)/2.cos(75°-15°)/2
  =2sin 45°+cos30°
  =(2)^1/2+((3)^1/2)/2
  Similarly formula of
  Cos c+ Cos d=2cos(c+d)/2*cos(c-d)/2
  
  
• 9 years agoHelpfull: Yes(7) No(2)
• 2(1/2^1/2*3^1/2/2)=(3/2)^1/2
• 9 years agoHelpfull: Yes(1) No(0)
• (sin75+cos75)/(cos75+sin75)=1
  answer- 01.
• 9 years agoHelpfull: Yes(1) No(0)
• Sin 75 +sin(90-75)=sin 75+cos 75=t(let)
  So t^2=(sin 75+cos 75)^2
  t^2=1+sin150
  t^2=1+Sin(180-30)
  t^2=1+1/2
  t=Sqr root(3/2). Ans
• 9 years agoHelpfull: Yes(1) No(0)