How to use the power reduction formulas to derive the half-angle formulas.
How to define the sine ratio and identify the sine of an angle in a right triangle.
How to define the cosine ratio and identify the cosine of an angle in a right triangle.
How to define the tangent ratio and identify the tangent of an angle in a right triangle.
How to use inverse trig functions to find angles in right triangles.
How to evaluate expressions like tan(sin (4/5))^(-1).
How to find the vertical asymptotes of secant, cosecant, and cotangent.
How radioactive elements change their identities through transmutation.
How to define the properties of real numbers.