Kpoprocks21
Kpoprocks21 Kpoprocks21
  • 17-06-2016
  • Mathematics
contestada

Use the half-angle identity to find the exact value of sin 105 degrees.
Please help

Respuesta :

caylus
caylus caylus
  • 17-06-2016
Hello,

cos 2a=1-2sin²a==>2sin²a=1-cos2a

cos (105°*2)=-cos(30°)=-√3/2
==>2sin²105°=1+√3 /2=(2+√3)/2
==>sin²105°=(2+√3)/4
==>sin 105°=1/2*√(2+√3)

Answer Link

Otras preguntas

a population decrease from 404 million to 288 million .which of the following is the percent decrease of the population
one number is 6 more than another.  Their product is is 520.  Find the numbers
why does the earth not lose its heat as quickly at night as the moon does?
one number is 6 more than another.  Their product is is 520.  Find the numbers
Where are most faults located? And what is a fault in science terms?
Where are most faults located? And what is a fault in science terms?
how many stars are there in america's flag ?
how many stars are there in america's flag ?
one number is 6 more than another.  Their product is is 520.  Find the numbers
How do you do y divided by 9=12?