Answers

2014-08-19T20:48:09+05:30
To calculate sin 75 degrees
Use identity sin(a+b)=sin(a)cos(b) + sin(b)cos(a) 
sin 75 = sin(30+ 45)
i.e. sin30cos45 +sin45cos30
     1/2*root2/2 + root3/2*root2/2
    =root2/4+root6/4
    =(root2 + root6)/4
   Calculating with calculator we get
   sin 75 (approximately)=0.9659
 
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  • Brainly User
2014-08-19T22:34:20+05:30
Sin 75=sin(45 + 30)
=(sin 45 ×.cos 30) + (cos 45 × sin 30)        As[sin(x+y)= sin x.cos y+ sin y.cos x]
=(1÷√2)×(√3÷2) + (1÷√2)×(1÷2)
=(√3+1)÷2√2    {ans}
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