Sum and Difference
1. sin(3π-x) = sinx
Remember to work with one side of the equation at a time
2. sin[(π/6)+x] = (1/2)(cosx + √3sinx)
3. sin(x+y) + sin(x-y) = 2sinxcosy
Remember to work with one side of the equation at a time
2. sin[(π/6)+x] = (1/2)(cosx + √3sinx)
3. sin(x+y) + sin(x-y) = 2sinxcosy
Double Angle
1. csc2Θ = (cscΘ) / (2cosΘ)
2. sec2Θ = (sec²Θ) / (2 - sec²Θ)
3. 1 + cos10y = 2cos²5y
2. sec2Θ = (sec²Θ) / (2 - sec²Θ)
3. 1 + cos10y = 2cos²5y
Half Angle
1. sec(x/2) = +/- √[(2tanx)/(tanx + sinx)]
2. tan(x/2) = cscx - cotx
3. -√[(1 + cos10x)/2] = -cos5x
2. tan(x/2) = cscx - cotx
3. -√[(1 + cos10x)/2] = -cos5x
