Home > A2C > Chapter 11 > Lesson 11.2.5 > Problem 11-104
11-104.
Without graphing, find where each of the following curves crosses the x-axis. (Find the exact points!) Homework Help ✎
f (x) = x2 − x − 12
f (x) = 2x2 − 3x − 9
f (x) = 2x2 + x − 7
f (x) = 3x2 − 2x + 7
f (x) = 3x3 + 2x2 − 8x
f (x) = 2x3 + 2x2 + 13x
Factor.
f(x) = (x + 3)(x − 4)
(−3, 0) and (4, 0)
Use the quadratic formula.
(−1.5, 0) and (3, 0)
See part (b).
See part (b).
It does not intersect the x-axis.
x is a common factor.
After you factor out x, factor or use the quadratic formula to find the roots of the rest.
See part (e).