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anonymous
 5 years ago
Find the exact value of sin22.5 (using the half angle formula)
i have the answer from the book, but i don't understand how they got there
anonymous
 5 years ago
Find the exact value of sin22.5 (using the half angle formula) i have the answer from the book, but i don't understand how they got there

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amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0half angle formula is obtained by manipulating the cos(2a) formula

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0cos(2a) has 3 equal solutions: cos^2  sin^2 1  2sin^2 2cos^2 1

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0cos(2a) = 12sin^2 is helpful in this case.. cos(2a) 1 = 2sin^2 cos(2a) 1  = sin^2 2

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0yes, i just don't understand how they simplified this: sqrt ((1  [sqrt2]/2) / 2) it is supposed to become sqrt ((2  sqrt2) / 4 )

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0they had steps, and it didn't explain how they got from step to step

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0so you wanna see it simplified then right?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0it just said "common denominator" and i couldn't figure out how to simplify it

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i guess yes, i just want it explained really

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0sqrt(1  cos(45) /2) = sin(22.5) right? sqrt([1  sqrt(2)/2]/2) we can seperate the "square root" sign to cover the top and bottom of the fraction seperately... for example: sqrt(a/b) = sqrt(a) / sqrt(b) right?

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0let me write it out this way so I dont confuse meself: sqrt(2) 1   2  2

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.02 sqrt(2)    2 2  2

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.02  sqrt(2)  2  2

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.02sqrt(2) 1  x  2 2

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.02  sqrt(2)  4 Do you follow that?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0i'm confused. i thought you multiplied 2sqrt(2) 2  x  2 1 because 2 is the reciprocal isnt it?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0or am i completely wrong

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0lets take a look at a simpler example: 1/2  = 1/4 right? 2

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.0whenever we divide by a fraction we turn it over an multiply instead. 1/2  = 1/2 * 1/2 = 1/4 2 1/3  = 1/3 * 1/2 = 1/6 2

amistre64
 5 years ago
Best ResponseYou've already chosen the best response.07  = 7 * (3/1) = 21 1/3

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0ohhhhhh got it thnks!
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