ans =

Your value in (i) for f(1.2) is 49020.80113638172, so when you round to 1 decimal, it becomes 49020.8 which in engineering notation is 4.9021e4 because of rounding the right most digit.

You should reread the question to understand why you are not getting 4.9 as answer (hint:question is asking a where f(1.2) = a * 10^n ) :)

syms x

f = exp(9*x); g = log(sqrt(x));

% (i)

f_at_x = subs(f,x,1.2); % evaluates f(x = 1.2) as symbolic

format long % change displasy setting

f_at_x = double(f_at_x) % converts to double (real)

f_at_x_rounded = round(f_at_x,1) % ??? round to 1 decimal place

format bank % change displasy setting

f_at_x_rounded

For part ii, log(x^n) = n*log(x) so both expressions are equivalent

fun1 = @(x) 0.5*log(exp(9*x));

fun2 = @(x) log(exp(4.5*x));

fun1(1.2) == fun2(1.2) % are they equal?