Answer:
The correct option is d
[tex]f(1) = -5[/tex]
[tex]f(2) = 11[/tex]
The correct option is d
The correct option is c
the correct option is b
Step-by-step explanation:
The given equation is
[tex]f(x) = x^4 + x -7 =0[/tex]
The give interval is [tex](1,2)[/tex]
Now differentiating the equation
[tex]f'(x) = 4x^3 +7 > 0[/tex]
Therefore the equation is positive at the given interval
Now at x= 1
[tex]f(1) = (1)^4 + 1 -7 =-5[/tex]
Now at x= 2
[tex]f(2) = (2)^4 + 2 -7 =11[/tex]
Now at the interval (1,2)
[tex]f(1) < 0 < f(2)[/tex]
i.e
[tex]-5 < 0 < 11[/tex]
this tell us that there is a value z within 1,2 and
f(z) = 0
Which implies that there is a root within (1,2) according to the intermediate value theorem