Practice Intermediate Value Theorem in Math

Use these practice problems to test your method after reviewing the concept explanation and worked examples.

Quick Recap

If ff is continuous on the closed interval [a,b][a, b] and NN is any value between f(a)f(a) and f(b)f(b), then there exists at least one cc in (a,b)(a, b) such that f(c)=Nf(c) = N.

A continuous function can't skip values. If you start below a line and end above it, you must cross it somewhere. It's like driving from sea level to a mountaintopβ€”you pass through every elevation in between.

Showing a random 20 of 50 problems.

Example 1

easy
State the two hypotheses required to apply the IVT on [a,b][a,b].

Example 2

easy
If ff is continuous and f(2)=f(5)=3f(2) = f(5) = 3, does IVT guarantee ff takes the value 10 on [2,5][2,5]?

Example 3

medium
Show the equation x=cos⁑(x)x = \cos(x) has a solution in [0,1][0,1].

Example 4

easy
Let f(x)=x2βˆ’5f(x)=x^2-5. Use IVT to show ff has a root in (2,3)(2,3).

Example 5

medium
Show f(x)=ex+x=2f(x) = e^x + x = 2 has exactly one solution, locating an interval.

Example 6

medium
Show f(x)=x3+xβˆ’1f(x) = x^3 + x - 1 has a root in (0,1)(0, 1).

Example 7

medium
Show sin⁑x=x2\sin x = \frac{x}{2} has a positive solution.

Example 8

hard
Show that the polynomial p(x)=x5βˆ’4x3+xβˆ’1p(x)=x^5-4x^3+x-1 has at least three real roots.

Example 9

medium
Can IVT be applied to f(x)=1xf(x) = \frac{1}{x} on [βˆ’1,1][-1, 1] to conclude it attains the value 0? Explain.

Example 10

hard
Show that every continuous function f:[0,1]β†’[0,1]f:[0,1] \to [0,1] has a fixed point.

Example 11

medium
Show that f(x)=x4βˆ’3xβˆ’1f(x)=x^4-3x-1 has a root in (1,2)(1,2).

Example 12

challenge
Show f(x)=x3βˆ’3x+1f(x) = x^3 - 3x + 1 has three real roots by locating sign changes.

Example 13

medium
Given continuous ff with f(1)=2,f(2)=βˆ’1,f(3)=4f(1)=2, f(2)=-1, f(3)=4, what is the minimum number of roots IVT guarantees on [1,3][1,3]?

Example 14

easy
True or false: IVT guarantees exactly one cc with f(c)=Nf(c)=N.

Example 15

medium
Prove every odd-degree polynomial p(x)p(x) has at least one real root.

Example 16

easy
Why must ff be continuous on the CLOSED interval [a,b][a,b] for IVT?

Example 17

medium
A continuous ff maps [0,1][0,1] into [0,1][0,1]. Show ff has a fixed point (f(c)=cf(c)=c).

Example 18

easy
A continuous function has f(βˆ’1)=2f(-1)=2 and f(2)=2f(2)=2. Does IVT guarantee f(c)=0f(c)=0 for some c∈(βˆ’1,2)c \in (-1,2)?

Example 19

medium
ff is continuous, f(0)=2f(0)=2, f(4)=2f(4)=2. Must ff take the value 11 on (0,4)(0,4)?

Example 20

easy
A continuous function has f(0)=1f(0) = 1 and f(3)=7f(3) = 7. Is there a cc with f(c)=4f(c) = 4?