5 + 3

1/2 + 1/3

1. /2 + 1/3

N[1/2 + 1/3]

N[1/2 + 1/3, 2]

N[1/2 + 1/3, 10]

Pi

N[Pi]

N[Pi, 20]

N[E, 20]

13*15

195/13

195/17

195/17.

3^6

Pi^3

Pi^3.

1.5*10^4

N[360 Degree]

N[57.3 Degree]

Sin[Pi/4]

Sin[Pi/4. ]

Sin[Pi/5]

Sin[Pi/5. ]

?Sin

x = {1, 2, 3}

x^2

x^10

ListPlot[{{1, 2}, {2, 4}, {3, 7}}]

ListPlot[{{1, 2}, {2, 4}, {3, 7}}]

SetOptions[ListPlot, Prolog -> PointSize[0.02]]

ListPlot[{{1, 2}, {2, 4}, {3, 7}}]

SetOptions[ListPlot, Prolog -> PointSize[0.02], 
      TextStyle -> {FontSize -> 18}]

Plot[Sin[x], {x, 0, 7}]

Plot[Sin[x], {x, 0, 7}]

SetOptions[Plot, TextStyle -> {FontSize -> 18}]

ParametricPlot[{(t/(2*Pi))*Cos[2*Pi*t], -(t/(2*Pi))*
          Sin[2*Pi*t]}, {t, 0, 3}]

ParametricPlot[{(t/(2*Pi))*Cos[2*Pi*t], -(t/(2*Pi))*
          Sin[2*Pi*t]}, {t, 0, 3}]

SetOptions[ParametricPlot, 
      TextStyle -> {FontSize -> 18}]

Dt[x^2, x]

?x

Clear[x]

Dt[x^2, x]

Dt[Sin[Sqrt[5 + x^2]], x]