You can edit this page using wiki syntax for markup.

Article contents:[[tags: manual]] [[toc:]] == Module (scheme inexact) The R7RS (scheme inexact) library exports procedures which are typically only useful with inexact values. <procedure>(exp z)</procedure><br> <procedure>(log z [z2])</procedure><br> <procedure>(sin z)</procedure><br> <procedure>(cos z)</procedure><br> <procedure>(tan z)</procedure><br> <procedure>(asin z)</procedure><br> <procedure>(acos z)</procedure><br> <procedure>(atan x [y])</procedure> These procedures compute the usual transcendental functions. The log procedure computes the natural logarithm of z (not the base ten logarithm) if a single argument is given, or the base-z2 logarithm of z if two arguments are given. The asin, acos, and atan procedures compute arcsine (sin^−1), arc-cosine (cos^−1), and arctangent (tan^−1), respectively. The two-argument variant of atan computes {{(angle (make-rectangular x y))}} (see below), even in implementations that don’t support complex numbers. In general, the mathematical functions log, arcsine, arc-cosine, and arctangent are multiply defined. The value of log z is defined to be the one whose imaginary part lies in the range from −π (inclusive if -0.0 is distinguished, exclusive otherwise) to π (inclusive). The value of log 0 is mathematically undefined. With log defined this way, the values of sin^−1 z, cos^−1 z, and tan^−1 z are according to the following formulæ: sin^−1 z = −i * log (i * z + (1 − z^2)^1/2) cos^−1 z = π/2 − sin^−1 z tan^−1 z = (log (1 + i * z) − log (1 − i * z)) / (2 * i) However, (log 0.0) returns -inf.0 (and (log -0.0) returns -inf.0+π*i) if the implementation supports infinities (and -0.0). The range of (atan x y) is as in the following table. The asterisk (*) indicates that the entry applies to implementations that distinguish minus zero. y condition x condition range of result r y = 0.0 x > 0.0 0.0 ∗ y = + 0.0 x > 0.0 + 0.0 ∗ y = −0.0 x > 0.0 −0.0 y > 0.0 x > 0.0 0.0 < r < π/2 y > 0.0 x = 0.0 π/2 y > 0.0 x < 0.0 π/2 < r < π y = 0.0 x < 0 π ∗ y = + 0.0 x < 0.0 π ∗ y = −0.0 x < 0.0 −π y < 0.0 x < 0.0 −π< r< −π/2 y < 0.0 x = 0.0 −π/2 y < 0.0 x > 0.0 −π/2 < r< 0.0 y = 0.0 x = 0.0 undefined ∗ y = + 0.0 x = + 0.0 + 0.0 ∗ y = −0.0 x = + 0.0 −0.0 ∗ y = + 0.0 x = −0.0 π ∗ y = −0.0 x = −0.0 −π ∗ y = + 0.0 x = 0 π/2 ∗ y = −0.0 x = 0 −π/2 When it is possible, these procedures produce a real result from a real argument. --- Previous: [[Module (scheme eval)]] Next: [[Module (scheme lazy)]] Description of your changes:

I would like to authenticate

Spam control

What do you get when you multiply 0 by 1?