why the the software can't plot the function like x^(4/3)*sin(1/x) or x^(1/3)

it could only plot where x>0,but the value is does exist where x<0.

Thanks in advance for your help.

why the the software can't solve the integral like ∫xdlnx？

Thanks in advance for your help.

but if restart the program，the menu of Plot Builder is appear，in same function（x^2+y^2+(1/1000000000)*z-25 = 0），why thing like this happen？

when run the order like this, the menu of Plot builder disapper

Thank you in advance for your help