Suppose a person wants to travel d miles at a constant speed of left parenthesis 60 plus x right parenthesis(60+x) mi/hr, where x could be positive or negative. the time in minutes required to travel d miles is upper t left parenthesis x right parenthesis equals 60 upper d left parenthesis 60 plus x right parenthesis superscript negative 1t(x)=60d(60+x)−1. a. given the linear approximation to t at the point xequals=0 is upper t left parenthesis x right parenthesis almost equals upper l left parenthesis x right parenthesis equals upper d left parenthesis 1 minus startfraction x over 60 endfraction right parenthesist(x)≈l(x)=d1− x 60, approximate the amount of time it takes to drive 8181 miles at 5858 mi/hr. b. what is the exact time required?