find the exact value of Tan (x/2) if cos x=3/5 where 180
2007-03-16
16:02:40
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3 answers
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asked by
Spirit of Vengeance
2
in
Science & Mathematics
➔ Mathematics
Use the half-angle identity:
tan(B/2) = (1 − cos B) / sin B
Since cos x = 3/5, we know that sin x = -4/5 since x is in quadrant 3.
tan(x/2) = (1-3/5)/(-4/5) = (2/5)(-4/5) = -1/2
Actually, upon further reflection, the question is not possible. In quadrant 3, cosine x should be negative, so it can't be 3/5!
2007-03-16 16:08:43 · answer #1 · answered by jenh42002 7 · 1⤊ 0⤋
x lies in the 3rd quadrant where cos x is negative and therefore cannot = 3/5. This problem cannot be solve as it presents an impossible situation.
2007-03-16 16:18:54 · answer #2 · answered by ironduke8159 7 · 0⤊ 0⤋
take the arccos(3/5), then plug into the equation tan(x/2).
2007-03-16 16:06:20 · answer #3 · answered by mr.quark 2 · 0⤊ 0⤋