/7 + x \ lim tan|------| x->15+ \15 - x/
Limit(tan((7 + x)/(15 - x)), x, 15)
<-oo, oo>
= 1.0400499674463
/7 + x \ lim tan|------| x->15- \15 - x/
= 0.349876907110641
1.0400499674463