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Which equation is a trigonometric identity?

Which equation is a trigonometric identity?-example-1
User Shane
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1 Answer

2 votes
Options A and D are trying to confuse you.
The real identity that looks similar to them is
sin^2 x + cos^2 x = 1
Options A and D are both incorrect and are not identities.

From options B and C, option B is the correct one.
By definition we have:
sin x = opp/hyp
cos x = adj/hyp
tan x = opp/adj

If you divide sin x by cos x and simplify, you get opp/adj, which is exactly what the tangent is.

The answer is B.
User DavidGamba
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7.5k points