Synonyms for x-intercepts: zeros, roots, solutions

Algebra 2 Solving for x-intercepts

Name Block _________ Date

Synonyms for x-intercepts: zeros, roots, solutions

Standard Form y = ax2 + bx + c

Vertex Form y = a (x-h)2 + k

Intercept Form y = (x ? p) (x ? q)

1) Set equal to 0

1) Set equal to 0

1) Set equal to zero

2) Factor

2) Get (x-h)2 alone

2) Solve

3) Solve

3) Square root both sides

4) Get x alone

Graphing Calculator

1. Graph the equation.

2. Check & adjust the window so the points where the graph crosses the x-axis can be seen.

3. Press the calc key (2nd trace).

4. Press 2 (zero).

5. Move the cursor to a position that is left (bound) of the x-intercept and press enter.

6. Move the cursor to a position that is right (bound) of the x-intercept and press enter.

7. Guess? Press enter a second time.

8. The coordinates of the x-intercept will be displayed on the view screen.

(Note the y-value should always be zero)

9. Repeat for all roots of the equation.

Problems 1. y = x2 ? 2x ? 3

4. y x 3 2 4

2. y = x2 + 3x + 2 5. y x 2 9

3. y = x2 ? 9x +20

6. y x 1 2 9

7. 3x2 + 8x ? 3 = 0 10. 2x2 ? x = 21 13. 3x2 + x ? 3 = 2x2 + 3x

8. x2 ? 16 = 0 11. x2 = 36 14. x2 + 3x = -2

9. x2 ? 81 = 0 12. 8x2 +5x ? 4 = 2x2 ? 8x +1 15. ?x2 ? 4x ? 4 = 0

16. x2 = 36 19. 2(x ? 6)2 ? 45 = 53 22. x2 = 121

17. x2 ? 9 = 0 4

20. 2x2 + 1 = 40 2

23. 3x2 = 108

18. x2 + 1 = 41 21. ? (x ? 16)2 = 10 24. ?x2 ? 12 = -87

25. x2 1 11 25

28. x2 + 4x = -4

26. 4(x + 1)2 = 100 29. 2x2 + 7x ? 4 = 0

27. 5(x ? 7)2 = 135 30. ?x2 + 10x ? 21 = 0

Practice Problems: pg 261 #65 - 72, 74 ? 78, pgs 267 and 268 #52-68 evens only

 ................
................

In order to avoid copyright disputes, this page is only a partial summary.

Google Online Preview   Download