4.15 Investigate the use of back-propagation learning employing a sigmoidal nonlinearity to achieve one-to-one mappings, as described here: 1, f(x)=, 2.f(x)=logi0x, 1 x 10 3,f(x) = exp(-x), 1 x 10 4. f(x) -sin x 1 sxs100 x 0sxs 2 4.15 Investigate the use of back-propagation learning employing a sigmoidal nonlinearity to achieve one-to-one mappings, as described here: 1, f(x)=, 2.f(x)=logi0x, 1 x 10 3,f(x) = exp(-x), 1 x 10 4. f(x) -sin x 1 sxs100 x 0sxs 2