Prove (from the definition) that if f(x) tends to L as x tends to a then 2f(x) tends to 2L as x tends to a
Now we can suppose (For all epsilon>0) (There exists delta >0) (For all x E X)
0<|x-a|<delta implies |f(x) - L| < epsilon.
Now we need to prove that 2f(x) tends to 2L as x tends to a.
I'm struggling a bit with how to do this..