Can anybody show me how to do this half angle identity problem step by step? i always seem to be missing something

Step-by-step explanation:

It is given that θ is between 270° and 360°, which means that θ is located in Quadrant IV ⇒ (x > 0, y < 0).  Furthermore, the half-angle will be between 135° and 180°, which means the half-angle is in Quadrant II ⇒

It is given that sin θ =  ⇒  y = -7 & hyp = 25

Use Pythagorean Theorem to find "x":

x² + y² = hyp²

x² + (-7)² = 25²

x² + 49 = 625

x²         = 576

      x   =  24    

Use the "x" and "hyp" values to find cos θ:

Lastly, input cos θ into the half angle formula:

Reminder: We previously determined that the half-angle will be negative.

step-by-step explanation:

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