21. The voltage V, in an electric circuit is measured in millivolts and is given by the formula I' = 0.2sin0.1x (7 - 0.5) + 0.3. where I is the time in seconds from the start of an experiment. Use the graph of the function to estimate how many seconds in the 40 second interval starting at 7 =0 during which the voltage is below 0.21 mV. A. 7.03 B. 14.06 C. 12.97 D. 27.16 21. 22. Determine the range of the function y = a cos x - + b, where a