Determine the absolute and percent relative uncertainty expressing the result in the correct number of significant digits
a.) 6.2 (+-0.2)-4.1(+-0.1)
b.)[9.23(+-0.03)][4.21(+-0.20}/21.1(+-0.2)
c.)log[3.1415(+-0.001)]
d) log[(0.104(+-0.0060)]^1/2 /0.0511(+-0.00090]