Find the principal arguments of the 5 roots of the polynomial:p(z)=z^5-5*z^4-5*z-5,and enter a decimal approximation to the largest principal argument in the box below.  Your approximation should be correct to 10 significant figures

Can some one tell me how to write in maple？correct answer is 2.691121659

Find, to 10 significant figures, the unique turning point x0 of f(x)=3sin(x^4/4)-sin(x^4/2)in the interval [1,2] and enter it in the box below.x0=？

How to write this in maple？