Answer: [tex]c = 1.2[/tex]
Step-by-step explanation:
First, it is needed to determined the values for x = 1 and x = 2:
[tex]f(1) = -1, f(2)=4[/tex]
The sign change within the interval is the most sound evidence of the root existence. According to the Intermediate Value Theorem, there is a number [tex]c[/tex] such that [tex]f(c) = 0[/tex]. Another finding is that [tex]c[/tex] is closer to 1 than to 2.
[tex]c = a + \frac{b-a}{f(b)-f(a)}\cdot[f(c)-f(a)][/tex]
[tex]c = 1 + \frac{2-1}{4-(-1)}\cdot[0-(-1)] \\c = 1.2[/tex]