Area of a circle "ds" over the whole circle formula_33 is just the arc length, which is its circumference, so this shows that the area "A" enclosed by the circle is equal to formula_34 times the circumference of the circle. Note that the area of a semicircle of radius r can be computed by the integral formula_35. By trigonometric substitution, we substitute formula_36, hence formula_37 The last step follows since the trigonometric identity formula_42 implies that formula_43 and formula_44 have equal integrals over the interval formula_45, using integration by substitution. But on the other hand, since formula_46, the sum of the two integrals is
Straight from the Desk Straight from the Desk Straight from the Desk is a live album by Ian Dury & the Blockheads recorded on 23 December 1978 at the Ilford Odeon, Ilford, East London. There is little information available about the album, other than what can be heard on the record. During the performance of "Billericay Dickie" the audience break the venue's floor, presumably in excitement causing Dury to warn the audience to mind the hole as an introduction to "Hit Me with Your Rhythm Stick" and mention it repeatedly later in the set. Dury forgets the words totally on "There Ain't Half Been