Double Angle Formulas Worksheet with Answer Key

What's on the worksheet

1. Each expression is one side of a double angle formula.
   4\sin 75^\circ\cos 75^\circ2\cos^2\dfrac{3\pi}{8} - 1\dfrac{2\tan 67.5^\circ}{1 - \tan^2 67.5^\circ}\dfrac{1}{2} - \sin^2\dfrac{5\pi}{8}
2. Simplify each expression to one or two terms.
   (\sin x - \cos x)^2\dfrac{\cos 2x}{\cos x - \sin x}\dfrac{\sin 2x}{1 - \cos^2 x}1 - 8\sin^2 x\cos^2 x
3. Angle θ has θ + θ = 1713 and 0^ < θ < 45^.
4. Angle a has a = 35 with 0 < a < π2, and angle b has b = 1237 with π2 < b < π.
5. Show that 2x + x 2x + x + 1 = x wherever the left side is defined.
6. Diego lays out a rectangular herb bed inside a semicircular garden plot of radius 22 meters.