FIR Filtering using firpm function.

Hi I want to design a low pass filter which passes until 0.05hz and blocks frequencies over 0.1hz.

And also it is required to design it as a differentiator filter.

The frequency response of the filter is :

|H(w) - jw| < 0.01, 0 <= w <= 2*pi*0.05

|H(w)| < 0.01, 2*pi*0.1 <= w <= 2*pi*0.5

And also low pass diffrentiator deviates less than 0.01.

I wrote the code below but it seems it is not correct.

Can someone help me please.

h=firpm(61,[0.05*pi*2 0.1*pi*2],[0.01 0],"differentiator");