916 (a) Find the eccentricity, (b) identify the conic, (c) give an equation of the directrix, and (d) sketch the conic.

Exam2StudySmartQuestions 4/9/1611:51PM BiologicalFoundations o Whenaneuronsendsasignal,itissendinganelectricalimpulsedownitsbody.Itstart inthedendrites,wheretheactionpotentialfromanotherneuronisreceived.The neurotransmittersfromthepresynapticneuroncausesligandgatedsodiumchannelto open.Thisinfluxofsodiumthrowsoffthethreshold,whichis-70mV.Ifthemembrane potentialreachesthreshold,moreandmoresodiumchannelswillopenandtheneuron willdepolarize,sendingdowntheactionpotential.Astheactionpotentialtravelsdown theaxon,moresodiumchannelsopen.Aftertheithastraveledthelengthoftheaxon, sodiumchan