graph g(x)=4(x^3)-24x+9 on a calulator and estimate the local maxima and minima.

the answers are either
a)The local maximum is about –13.627417. The local minimum is about 31.627417.
b)The local maximum is about 31.627417. The local minimum is about –13.627417.
c)The local maximum is about 13.627417. The local minimum is about –31.627417.
d)The local maximum is about 22.627417. The local minimum is about –22.627417.

my calculator isn't working so i don't know what to do. Thanks for any help.

3 answers

There is no need for a calculator.

The min or max are at x=+/-sqrt(2)

so I get

Maximum is 32.62742 (x=-(2^0.5)
Minimum is -13.6274 (x=2^0.5)

which is a)

But check my working.

I see. thank you!

y=-3x^2+9x-1