A phone charger transforms AC into DC electricity to charge your mobile phone if the charger is 85% efficient. a) What is the energy needed to obtain 1200 J of DC?

Let f(x) = x4- 8x2 . find the relativeextrema of this function using the second derivative test.

Adelivery truck leaves a warehouse and travels 2.60 km north. the truck makes a left turn and travels 1.25 km west before making another right turn to travel 1.40 km north to arrive at its destination. what is the magnitude and direction of the truck's displacement from the warehouse?

Find the equation for the plane through upper p 0 left parenthesis negative 4 comma negative 8 comma negative 5 right parenthesis perpendicular to the following line. xequalsnegative 4 minus t, yequalsnegative 8 plus 2 t, zequals3 t, minusinfinityless thantless thaninfinity