4243.6-4000=243.6/4000= 0.06
Interest rate 0.06%
Given that a polynomial function P(x) has rational coefficients.
Two roots are already given which are i and 7+8i,
Now we have to find two additional roots of P(x)=0
Given roots i and 7+8i are complex roots and we know that complex roots always occur in conjugate pairs so that means conjugate of given roots will also be the roots.
conjugate of a+bi is given by a-bi
So using that logic, conjugate of i is i
also conjugate of 7+8i is 7-8i
Hence final answer for the remaining roots are (-i) and (7-8i).
Use the midpoint formula and solve. work pictured below
The total cost is given by the equation:
C(t) = 45 + 25(h-1) where h is the number of hours worked.
We can check for each option in turn:
Option A:
Inequality 5 < x ≤ 6 means the hour is between 5 hours (not inclusive) to 6 hours (inclusive)
Let's take the number of hours = 5
C(5) = 45 + (5-1)×25 = 145
Let's take the number of hours = 6
Then substitute into C(6) = 45 + (6-1)×25 = 170
We can't take 145 because the value '5' was not inclusive.
Option B:
The inequality is 6 < x ≤ 7
We take number of hours = 6
C(6) = 25(6-1) + 45 = 170
We take number of hours = 7
Then C(7) = 25(7-1) + 45 = 195
Option C:
The inequality is 5 < x ≤ 6
Take the number of hours = 5
C(5) = 25(5-1) + 45 = 145
Take the number of hours = 6
C(6) = 25(6-1) + 45 = 170
We can't take the value 145 as '5' was not inclusive in the range, but we can take 170
Option D:
6 < x ≤ 7
25(6-1) + 45 < C(t) ≤ 25(7-1) + 45
170 < C(t) ≤ 195
Correct answer: C
