Question 869603
a)Find t when p=0.
{{{0.090t-0.015t^2=0}}}
{{{0.090t=0.015t^2}}}
{{{t=0.090/0.015}}}
{{{t=6}}} hours
b) 15 minutes = 1/4 hour
{{{p=0.090(1/4)-0.015(1/16)}}}
{{{p=0.0225-.0009375}}}
{{{p=0.0215625}}}
c) {{{graph(300,300,-2,8,-1,2,0.090x-0.015x^2)}}}
Looks for the two points when {{{p=0.12}}}
{{{0.090t-0.015t^2=0.12}}}
{{{-15t^2+90t-120=0}}}
{{{t^2-6t+8=0}}}
{{{(t-2)(t-4)=0}}}
Two solutions: {{{t=2}}} and {{{t=4}}}
So the difference is how long the drug is above 12%.
{{{DELTA=4-2=2}}}{{{hours}}}