// JavaScript Document
thepage="Dir/Inv Problems(3)"
//globals
refnumber=4
//11/18/02-netscape 7
totl=0
corrt=0
tried=0
missed=0
ptype=0
myans=0
theans=0
thesolution=""
miss=0
cat=0
a1=0;a2=0;b1=0;b2=0
theform="<form><input type=text size=6><input type=button value='Check Answer' onClick=parent.frames[1].screen(this.form)></form>"
relate=new Array(5)
relate[1]="directly"
relate[2]="inversely"
missing=new Array(5)
missing[4]="A<sub>1</sub>"
missing[2]="A<sub>2</sub>"
missing[3]="B<sub>1</sub>"
missing[1]="B<sub>2</sub>"
function parts(p1,p2,p3,p4,p5,p6){
	this.p1=p1
	this.p2=p2
	this.p3=p3
	this.p4=p4
	this.p5=p5
	this.p6=p6
}
sequat=new Array(5)
sequat[1]="A<sub>1</sub>/B<sub>1</sub>=A<sub>2</sub>/B<sub>2</sub>"
sequat[2]="A<sub>1</sub>*B<sub>1</sub>=A<sub>2</sub>*B<sub>2</sub>"
fequat=new Array(10)
fequat[4]="A<sub>1</sub>=A<sub>2</sub>*B<sub>1</sub>/B<sub>2</sub>"
fequat[2]="A<sub>2</sub>=A<sub>1</sub>*B<sub>2</sub>/B<sub>1</sub>"
fequat[3]="B<sub>1</sub>=A<sub>1</sub>*B<sub>2</sub>/A<sub>2</sub>"
fequat[1]="B<sub>2</sub>=A<sub>2</sub>*B<sub>1</sub>/A<sub>1</sub>"
fequat[8]="A<sub>1</sub>=A<sub>2</sub>*B<sub>2</sub>/B<sub>1</sub>"
fequat[6]="A<sub>2</sub>=A<sub>1</sub>*B<sub>1</sub>/B<sub>2</sub>"
fequat[7]="B<sub>1</sub>=A<sub>2</sub>*B<sub>2</sub>/A<sub>1</sub>"
fequat[5]="B<sub>2</sub>=A<sub>1</sub>*B<sub>1</sub>/A<sub>2</sub>"
pieces=new Array(5)
ansphrase=new parts("Since A and B are "," related, the relationship is described by the equation: ", ".<br> The missing variable is ",".<br> Rearranging the equation to solve for "," yields<br> ","<br> Substituting the known values and solving the equation:<br>")
question=new Array(10)
question[1]=new parts("A and B are directly related. Initially, it is found that A="," and B="," If A is changed to "," what will be the corresponding value of B?")
question[2]=new parts("A and B are directly related. Initially, it is found that A="," and B="," If B is changed to "," what will be the corresponding value of A?") 
question[3]=new parts("A and B are directly related. Initially, it is found that A="," and the value of B is unknown. If A is changed to "," it is found that B=",". What was the initial value of B?")
question[4]=new parts("A and B are directly related. Initially, it is found that B="," and the value of A is unknown. If B is changed to "," it is found that A=",". What was the initial value of A?")
question[5]=new parts("A and B are inversely related. Initially, it is found that A="," and B="," If A is changed to "," what will be the corresponding value of B?")
question[6]=new parts("A and B are inversely related. Initially, it is found that A="," and B="," If B is changed to "," what will be the corresponding value of A?") 
question[7]=new parts("A and B are inversely related. Initially, it is found that A="," and the value of B is unknown. If A is changed to "," it is found that B=",". What was the initial value of B?")
question[8]=new parts("A and B are inversely related. Initially, it is found that B="," and the value of A is unknown. If B is changed to "," it is found that A=",". What was the initial value of A?")
function startit(){
	clear()
	totl++
	document.forms[0].total.value=totl
	missed=0
	a1=number(100*Math.random(),3,3)
	a2=number(100*Math.random(),3,3)
	clear()
	power=Math.random()
	base=Math.ceil(100*Math.random())
	factor=Math.pow(base,power)
	//choose problem
	ptype=Math.ceil(8*Math.random())
	calcvalues(ptype)
	buildquest()
}
function calcvalues(ptype){
	if(ptype<5){
		cat=1
		miss=ptype
		b1=factor*a1
		b2=a2*b1/a1
	}
	else{
		cat=2
		miss=ptype-4
		b1=factor/a1
		b2=b1*a1/a2
	}
	b2=number(b2,3,3)
	b1=number(b1,3,3)
	}
function buildquest(){
if(ptype==1 || ptype==5){
	thequest=question[ptype].p1+a1+question[ptype].p2+b1+question[ptype].p3+a2+question[ptype].p4
	pieces[4]=b2
	}
if(ptype==2 || ptype==6){
	thequest=question[ptype].p1+a1+question[ptype].p2+b1+question[ptype].p3+b2+question[ptype].p4
	pieces[4]=a2
	}
if(ptype==3 || ptype==7){
	thequest=question[ptype].p1+a1+question[ptype].p2+a2+question[ptype].p3+b2+question[ptype].p4
	pieces[4]=b1
	}
if(ptype==4 || ptype==8){
	thequest=question[ptype].p1+b1+question[ptype].p2+b2+question[ptype].p3+a2+question[ptype].p4
	pieces[4]=a1
	}
	buildans()
	showquest(thequest)
}
function buildans(){
	if(ptype==1 || ptype==4 || ptype==7 || ptype==8)pieces[1]=a2;
		else pieces[1]=a1; 		
	if(ptype==3 || ptype==2 || ptype==7 || ptype==8)pieces[2]=b2;
		else pieces[2]=b1; 	
	if(ptype==1 || ptype==7)pieces[3]=a1;
	if(ptype==2 || ptype==8)pieces[3]=b1;
	if(ptype==3 || ptype==5)pieces[3]=a2;
	if(ptype==4 || ptype==6)pieces[3]=b2;
	lastpiece=pieces[1]+"*"+pieces[2]+"/"+pieces[3]+"="+pieces[4]
	theanswer=ansphrase.p1+relate[cat]+ansphrase.p2+sequat[cat]+ansphrase.p3+missing[miss]+ansphrase.p4+missing[miss]+ansphrase.p5+fequat[ptype]+ansphrase.p6+lastpiece
}

function screen(val){
	myans=val
	if(ptype==1 || ptype==5)theans=b2
	if(ptype==2 || ptype==6)theans=a2
	if(ptype==3 || ptype==7)theans=b1
	if(ptype==4 || ptype==8)theans=a1
	answer()
}
function answer(){
	if(tried==1)alert("You've already done this problem. Get a new one.");
	else{
	if(tried==2){totl++;document.forms[0].total.value=totl}
	attempts++
	if(myans>.95*theans & myans<1.05*theans){
		tried=1
		document.forms[0].results.value="correct"
		corrt++
		document.forms[0].correct.value=corrt
	}
	else{
		document.forms[0].results.value="incorrect"
		tried=2	
		}
	}
}