SOLUTION: using trig function values of 30, 45, and 60 degrees find the exact value: cos 15 degrees tan 75 degrees

Question 934048: using trig function values of 30, 45, and 60 degrees find the exact value:
cos 15 degrees
tan 75 degrees
Answer by lwsshak3(11628) (Show Source): You can put this solution on YOUR website!
using trig function values of 30, 45, and 60 degrees find the exact value:
cos 15 degrees
tan 75 degrees
***
cos 15=cos(45-30)=cos45*cos30+sin45*sin30=√2/2*√3/2+√2/2*1/2=√6/4+√2/4=(√6+√2)/4
tan 75=tan(45+30)=(tan45+tan30)/(1-tan45*tan30)=(1+√3/3)/(1-1*√3/3)=(1+√3/3)/(1-√3/3)
cos 15 degrees=(√6+√2)/4
tan 75 degrees=(1+√3/3)/(1-√3/3)
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