Use the half-angle identities to find the exact value of cos 15 degrees.
this is what i have so...
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Mathematics, 18.09.2019 18:00 cruzsuarezjanca
Use the half-angle identities to find the exact value of cos 15 degrees.
this is what i have so far:
cos15 degrees = cos1/2(30 degree) = sqrt (1+cos30)/2 = sqrt (1+ sqrt3/2)/ 2
but.. i don't understand how the cos30 turns into sqrt 3/2? ?
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