Let f(x) = (2)sqrt(x). If f(c)=f'(c) find the value of c

Answer 1

f(x) = 2√x = 2x^(1/2) ----> f(c) = 2√c
f'(x) = (1/2)(2)x^(-1/2) = 1/√x , ------> f'(c) = 1/√c
they are supposed to be equal, so
2√c = 1/√c
multiply both sides by √c
2c = 1

etc