Cogito
Integrated Math 2 · Chapter 2 · Lesson 3
Systems With a Quadratic
Where a line meets a curve.
12 problems · about 21 minutes · A-REI.C.7
Figure — use these to answer the problems
Warm Up
Straightforward practice. Get the method working first.
5 problemsy = x² and y = 16. What is the positive x value?
AnswerWhat does exactly one solution mean geometrically?
- The line touches the parabola without crossing it.
- The line is parallel to the parabola.
y = x² and y = 4. What is the positive x value?
Answery = x² and y = 9. Positive x value?
Answery = x² and y = 0. How many intersection points?
Answer
Build It Up
The same ideas with more to keep track of.
3 problemsy = x² and y = −4. How many intersection points?
Answery = x² and y = 2x. What is the non-zero x value?
Answery = x² and y = x + 6. What is the smaller x value?
Answer
Stretch Yourself
Mixed problems. Work out what kind of question it is before you start.
4 problemsPut the solving process in order.
Write 1 to 4 in the boxes to put these in order.
- Substitute the linear equation into the quadratic.
- Rearrange so one side is zero.
- Solve the resulting quadratic for x.
- Substitute each x back to find its y.
y = x² and y = 25. Positive x value?
AnswerThe Intersection
y = x² and y = x + 6. What is the larger x value?
AnswerThe Matching y
Same system. What is y when x = 3?
Answer