Answer:
• cos(α/2) = (4/17)√17
• sin(α/2) = (√17)/17
Step-by-step explanation:
The appropriate hαlf-angle identities are:
sin(α/2) = √((1 -cos(α))/2)
cos(α/2) = √((1 +cos(α))/2)
Putting in your given values for cos(α), we have ...
cos(α/2) = √((1 +15/17)/2) = √(16/17) = 4(√17)/17
sin(α/2) = √((1 -15/17)/2) = √(1/17) = (√17)/17
