Question

If 270<theta<360and cos=1/4 find tan theta/2

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Answer 1

− 3 √ 10 10

$1+cos2a=2cos2a2cos2(t2)=1+cost=1+45=95cos2(t2)=910cos(t2)=±3√10=3√1010.$

Explanation:

Use trig identity:

Since t is in Quadrant IV, then, t/2 is in Quadrant II.

cos (t/2) is negative.

cos

$(t2)=−3√1010$

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