π rad = 180°
Using radian mode on the calculator you can solve an equation and give answers either in decimals or multiples of π. For radian equations, the three formulas for general solutions are:
These are analogous to the formulas for degrees.
Example
Solve for 0≦x≦π the equation
Using the sine formula,
n=0 ⇒ x=1.74 rad
n=1 ⇒ x=2.97 rad
Example
Giving your answers as multiples of π, solve for 0≦x≦2π the equation
Using the cosine formula,
n=1 ⇒ x=23/24π, 19/24π
n=2 ⇒ x=47/24π, 43/24π
Example
Giving your answers as multiples of π, solve for 0≦x≦4π the equation
Using the tan formula,
n=0 ⇒ x=π/3
n=1 ⇒ x=7π/3, 5π/3
n=2 ⇒ x=11π/3
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