Learning Guide Learning Guide

164 • Chapter 5: Evaluation and SimplificationMaple cannot simplify this, as the result is different for positive andnegative values of a. Stating an assumption about the value of a allowsMaple to simplify the expression.> assume( a>0 );> sqrt(a^2);a~The tilde (~) on a variable indicates that an assumption has beenmade about it. New assumptions replace old ones.> assume( a sqrt(a^2);−a~Use the about command to get information about the assumptionson an unknown.> about(a);Originally a, renamed a~:is assumed to be: RealRange(-infinity,Open(0))Use the additionally command to make additional assumptionsabout unknowns.> assume(m, nonnegative);> additionally( m about(m);Originally m, renamed m~:is assumed to be: 0Many functions make use of the assumptions on an unknown. Thefrac command returns the fractional part of a number.> frac(n);frac(n)> assume(n, integer);> frac(n);