Algebra I Help Sheet for EOCT
v SOLVING EQUATIONS
Ø Look for phrases like:
§ “What is the value of…”
§ “Solve for…”
Ø Steps to follow:
§ Split the problem into 2 sides using the = sign.
§ Put one side of the equation in Y1=
§ Put the other side of the equation in Y2 =
§ ZOOM FIT (#0)
§ 2nd TRACE
§ #5 INTERSECT
§ ENTER 3 times
v FINDING AN EQUATION TO MATCH A TABLE
Ø Look for phrases like:
§ “Which equation describes the data in the table?”
§ “Which function includes all of the data points in the table?”
Ø Steps to follow:
§ STAT
§ EDIT
§ Be sure you type the x list in L1
§ Be sure you type the y list in L2
§ Go back to STAT
§ Over to CALC
§ If most choices have “plain” x’s ►#4 (LinReg (ax + b))
§ If most choices have x2 ►#5 QuadReg
§ ENTER
Ø OR YOU CAN DO THE FOLLOWING:
§ Type each answer choice it Y1 =
§ 2nd GRAPH to look at the table
§ Then find the table that matches the one you see in the calculator
v SOLVING A SYSTEM OF EQUATIONS (2 EQUATIONS TOGETHER)
Ø Look for phrases like:
§ “What are the coordinates of the intersection?”
Ø Steps to follow:
§ Make sure Y is by itself!
§ Then, go to Y =
§ ZOOM FIT (#0) ► If you don’t see an intersection ZOOM OUT or IN
§ 2nd TRACE
§ #5 INTERSECTION
§ ENTER 3 times
v DOMAIN AND RANGE
Ø Domain is the set of x values
§ On a graph, look for what value the x is at on the left and what value it is at on the right
Ø Range is the set of y values
§ On a graph, look for what value the y is lowest at and what value the y is highest at
Ø REMEMBER: an open circle means not included (< or >) and a closed circle means included (≤ or ≥)
v GIVEN A GRAPH AND LOOKING FOR EQUATION TO MATCH
Ø Look for phrases like:
§ “What function is best represented by the graph below?
§ “Which equation matches the graph?”
Ø Steps to follow:
§ Carefully type each equation in to Y1 =
§ Use either ZOOM STANDARD (#6) or ZOOM FIT (#0) to look at the picture
§ Pay close attention to how the graph crosses the y-axis or the x-axis
§ Use 2nd GRAPH (TABLE) to help as well
v GIVEN TWO POINTS AND LOOKING FOR EQUATION TO MATCH
Ø Look for phrases like:
§ “What equation would pass through these 2 points?”
Ø Steps to follow:
§ STAT
§ EDIT
§ Type the x-values (the first number in each set of parentheses) in L1
§ Type the y-values (the second number in each set of parentheses) in L2
§ STAT
§ Use blue arrows to go over to CALC
§ #4 LinReg (ax + b)
§ ENTER
v X- AND Y-INTERCEPTS
Ø Remember the x-intercept is where the graph crosses the x-axis
Ø Remember the y-intercept is where the graph crosses the y-axis
v EXPONENTS
Ø Add exponents when they are on the same level
Ø Multiply exponents when the exponent is being distributed inside of parentheses
Ø Subtract exponents if the same base is on the top and bottom of a fraction
Ø REMEMBER: Always use parentheses around a negative number if you are raising it to a power in the calculator.
v IF THE PROBLEM INVOLVES ANY GEOMETRY FORMULAS, USE THE FORMULA SHEET!
v WHEN IN DOUBT, PLUG THE ANSWER CHOICES IN TO THE FORMULA TO FIND THE CORRECT ANSWER!