SYMBOLIC AND NUMERIC COMPUTATION

( 2 + 3 )^3 - (3+4)/8

123456789/987654321 - 987654321/234567891

% // N

3^15

3.0^15

Sqrt[ Log[ Exp[ Sin[ Cos[ Tan[ 
           ArcSin[ ArcCos[ ArcTan[ Abs[1.5] ]]]]]]]]]

N[E]

N[Pi,536]

E^(2 I Pi) - 1

Sin[ Pi/4 ]

Sin[ 45 Degree ] // N

ArcTan[ Infinity ]

zz = 2 + 2 I

Re[zz] + Im[zz]

Abs[zz] + Conjugate[zz]

N[ Arg[zz] ] - N[ Pi/4]