Equation how to evaluate and obtain a value

Hi

I have create an equation

syms x 
f(x) = exp(5*x);
df(x) = diff(f,x);

and then I want to evaluate f and df when x = 2

f(2)
Df(2)

But the result is not a value. I obtain f(2) = exp(10) df(2) = 5 exp (10)

How can I calculate to obtain a value : f(2) = 2.2026e+04 df(2)= 1.1013e+05

Answer 1

[Andrei Bobrov]

Please try use function vpa:

syms x 
f(x) = exp(5*x);
df(x) = diff(f,x);
vpa(f(2))
vpa(df(2))

Answer 2

[John BG]

just change the type

syms x
f(x) = exp(5*x);
df(x) = diff(f,x);

double(f(2))
 =
     2.202646579480672e+04

and

double(df(2))
 =
     1.101323289740336e+05

if you find these lines useful would you please mark my answer as Accepted Answer?

To any other reader, if you find this answer of any help, please click on the thumbs-up vote link,

thanks in advance for time and attention

John BG

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