As a reminder:
Even Functions: Opposite inputs result in the same output: \(f(-x) = f(x)\).
Odd Functions: Opposite inputs result in opposite outputs: \(f(-x) = -f(x)\).
Are Sine/Cosine/Tangent even, odd, or neither?
Pick some angles on the unit circle and compare:
\(\cos(\theta)\) vs. \(\cos(-\theta)\)
\(\sin(\theta)\) vs. \(\sin(-\theta)\) and
\(\tan(\theta)\) vs. \(\tan(-\theta)\).
Solution
Cosine is Even: \(\cos(-\theta)=\cos(\theta)\)
Sine is Odd:\(\sin(-\theta)=-\sin(\theta)\)
Tangent is Odd: \(\tan(-\theta)=-\tan(\theta)\)