Okay...
Given that:
sin cos
66 degrees 0.9135 0.4067
104 degrees 0.9703 -0.2419
213 degrees -0.5446 -0.8387
Find sin 81 degrees
Hint: Double, Difference
Apparently I don't understand the concept. Thanks!
Hello, aigiqinf!
The hint refers to:
. . a Difference identity: .
. . two Double-Angle identities: .
We note that: .Given that: .
Find
Hint: Double, Difference
So: .
. . Since , we have: .
. . . . . . . . . . . . . . . .
Now substitute the values given in the table . . .