Question

f(t)=5^x sechx
f'(x)=?

Answer 1

Do you mean
f(x) = (5^x)*(sech x), or
f(x) = 5^(x sech x) ?

In the first case, use the differentiation rule for the product of two functions. The second can be solved using the rule for the function of a function

Answer 2

(5^x)*(sech x)