FNChireturns the value of the hyperbolic cosine integral ofx, Chi(x). Chi(x) is defined by the relation
whereγis Euler's number;γ= 0.57721566490153...
The real version of Chi(x) is only defined for positive values ofx. Large positive values ofxmay produce results greater than MAXREAL, the largest value representable.
Chi(x)
Errors
FNChicauses an HTBasic error if its argument is not of type REAL. It also causes an error if the value ofxis negative or zero or if Chi(x) would be greater than MAXREAL.