?

​
In[6]:=
Clear[f,x]​​f[x_Real]=Simplify[x*(x^2+9/4)/((x^2+3/2+x*Sqrt[x^2+2])*Sqrt[x^2+2]),x>=0]​​Evaluate[f[5]]​​Plot[f[x],{x,0,5},{PlotRange->Full,ImageSize->Medium}]​​Simplify[NIntegrate[f[x],{x,0,5}]]​​
Out[7]=
x
2
x
+
9
4

2
x
+2
2
x
+
2
x
+2
x+
3
2
Out[8]=
f(5)
Out[9]=
Out[10]=
2.26493