According to Moore's law the number of transistors that can be placed on an integrated circuit has doubled every 2 years. In 1971 there were only 2300 transistors on an integrated circuit. 

(a) Find an exponential function T(x) = Ca^x that gives the number of transistors on an integrated circuit x years after 1971. 

(b) Evaluate 7(40) and interpret your result. 

(c) Determine the year when integrated circuits first had 10 million transistors.