SOLUTION: Using the exact values of the sine and the cosine of 1/6 pie and 3/4 pie and one of the sum and difference formulas. show sin(7/12 pie)is 1/4(sqrt2 + sprt6)? i can work out the

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Question 924795: Using the exact values of the sine and the cosine of 1/6 pie and 3/4 pie and one of the sum and difference formulas. show sin(7/12 pie)is 1/4(sqrt2 + sprt6)?
i can work out the sin(7/12pie)=sin(1/4pie+1/3pie)=sin(1/4pie)cos(1/3pie)+cos(1/4pie)sin(1/3pie)=1/2sprt2*1/2+1/2sprt2*1/2sprt3=1/4(sprt2+sprt6)
i do not understand using the exact values of sin and cosin of 1/6 pie and 3/4pie????
Found 2 solutions by Alan3354, ewatrrr:
Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website!
I'm not doing any more problems with pie.
Use the Greek letter, pi.

Answer by ewatrrr(24785) (Show Source):
You can put this solution on YOUR website!

Hi
sin( 7π/12) = (1/4)(√2 + √6) is the exact value representation of sin( 7π/12)
that allows one to express sin( 7π/12) in terms of simple square roots rather
than in using a decimal representation derived from a calculator.
...
Although calculators use irrational numbers such as π, √2 ,√3 etc...
the decimal calculations are never 'exact' (...best we can do is a 'rounded off' representation)
...........
θ radians sin θ cos θ tan θ
0� 0 0 1 0
30� π/6 1/2 √3/2 √3/3
45� π/4 √2/2 √2/2 1
60� π/3 √3/2 1/2 √3
90� π/2 1 0 ─