If the terminal point determined by t is p(a, b), then (a) the terminal point p(x, y) determined by π−t is x= and y= ; (b) the terminal point p(x, y) determined by −t is x= and y= ; (c) the terminal point p(x, y) determined by π+t is x= and y= ; (d) the terminal point p(x, y) determined by 2π+t is x= and y=

Aspacecraft can attain a stable orbit 300 kilometers above earth if it reaches a velocity of 7.7 kilometers per second. the formula for a rocket's maximum velocity v in kilometers per second is vequalsminus0.0098tplusc ln upper r, where t is the firing time in seconds, c is the velocity of the exhaust in kilometers per second, and r is the ratio of the mass of the rocket filled with fuel to the mass of the rocket without fuel. find the velocity of a spacecraft whose booster rocket has a mass ratio of 20, an exhaust velocity of 2.1 km/s, and a firing time of 15 s. can the spacecraft achieve a stable orbit 300 km above earth?