f(12)=((212)+1)^0.5=25^0.5=5 (simply substitute 12 into the original function)To find f'(12) we need to first find the derivative of the function and then we can substitute 12 in like we did before.f'(x)=0.5(2x+1)^-0.5*(2)=(2x+1)^-0.5=1/((2x+1)^0.5)f'(12)=1/(2(12)+1)^0.5=1/25^0.5=1/5