This gives the meaning of the terms as generally understood in the middle of the 18th century. Robert Hooper's Physician's Vade-Mecum, published in 1812 has been used as a source of terms in the early 19th century; many of the terms mentioned are still in common use.
In either case, the value at x = 0 is defined to be the limiting value sinc(0) = 1. The normalization causes the definite integral of the function over the real numbers to equal 1 (whereas the same integral of the unnormalized sinc function has a value of Ï).
The answer is â30Â°. With inverse sine, we select the angle on the right half of the unit circle having measure as close to zero as possible. Thus sin-1(âÂ½) = â30Â° or sinâ1(âÂ½) = âÏ/6. In other words, the range of sin-1 is restricted to [â90Â°, 90Â°] or .