Given any one trigonometric relation, you can obtain the other five using simple identities.
If secθ = 5/2,
(secθ)^2 = (tanθ)^2 + 1 (Trigonometric Identity)
=> (5/2)^2 = (tanθ)^2 + 1
=> 25/4 - 1 = (tanθ)^2
=> 21/4 = (tanθ)^2
If sinθ is negative, and cosθ is positive,
=> tanθ = -(root(21/4))
Now, cotθ = (1/tanθ)
= (1/(21/4))
= -(root(4/21))
Use the Pythagorean identities rather than reference triangles . Find tanθ and cotθ if secθ = 5/2 and sinθ <0.
Please help ! Much appreciated !!
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