Can't find the maximum on the graph of a function

Hello! I'm not sure how to answer this homework problem I have. I've gotten halfway through the code and have done an fplot, but I can't find anything on how to plot the max of an fplot/find the max of an fplot. The problem is below:

This is my code so far:

t = [0:30];
h = height(t);
fplot(height(t),[0,30])
function h=height(t);
h=@(t) (-(9.8/2).*t.^2)+(125.*t)+500
end

Adding a max value just creates a huge error message, and I'm not sure why:

t = [0:30];
h = height(t);
fplot(height(t),[0,30])
[max_t,max_h]=max(height(t))
function h=height(t);
h=@(t) (-(9.8/2).*t.^2)+(125.*t)+500
end

Answer 1

[KSSV]

t = 0:30;
h =  (-(9.8/2).*t.^2)+(125.*t)+500 ;

[val,idx] = max(h) ; 
h_max = val ;
t_max = t(idx) ; 
plot(t,h)
hold on
plot(t_max,h_max,'*r')

[Nabiha Hasan]

This doesn't create the max value on the graph of the function; when I placed the code in, it just made an overlapping graph over the one I needed.

[madhan ravi]

Why not?, the answer proposed did your homework perfectly.

[Nabiha Hasan]

Yes, it definitely did. But I was wondering if there was any way to find the max of the function itself? When I used his code, it worked fine, but when I tried to find the max of the function height(t), it just told me it wasn't a numerical value.