Trig Fns - Identities
Interactive practice questions
Given $\cos\theta=\frac{4}{5}$cosθ=45 and $\sin\theta=\frac{3}{5}$sinθ=35:
a
Find the value of $\sin2\theta$sin2θ.
b
Find the value of $\cos2\theta$cos2θ.
c
Find the value of $\tan2\theta$tan2θ.
Easy9 min
Simplify $\cos^2\left(15^\circ\right)-\sin^2\left(15^\circ\right)$cos2(15°)−sin2(15°).
Easy1 min
Find the exact value of $\sin\frac{3\pi}{8}$sin3π8.
Express your answer with a rational denominator.
Easy2 min
Simplify $\frac{2\tan157.5^\circ}{1-\tan^2\left(157.5^\circ\right)}$2tan157.5°1−tan2(157.5°).
Easy1 min
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