Problem: Prove that the equation below is an identity: 2 sin2? – sin4? = (1 – cos2?)(1 + cos2?). Solution To prove that an equation is an identity, one must show that the Left Hand Side (LHS) of the equation is identical to its Right Hand Side (RHS). That is, LHS ? RHS. Proof LHS: 2 sin2?
This is the third in the series of problems involving transforming polygons into another polygon where the area is preserved. The first is about transforming a shape into another shape of the same area and the second is about transforming a quadrilateral into a triangle of the same area. The following problem builds on the
To solve the two problems below you need to know 1) The area of a circle is ?r2, with r as radius and that the area of a semicircle is of course half of the circle, ½?r2 and 2) the angle in a semicircle theorem. Problem 1 Prove that the area of the solid green semicircle