if k(x) = (x³ + 343)/(x + 7), complete the table and use the results to find lim x→ - 7 k(x). x - 7.1 - 7.01…

if k(x) = (x³ + 343)/(x + 7), complete the table and use the results to find lim x→ - 7 k(x). x - 7.1 - 7.01 - 7.001 - 6.999 - 6.99 - 6.9 k(x) complete the table. x - 7.1 - 7.01 - 7.001 - 6.999 - 6.99 - 6.9 k(x) (round to three decimal places as needed.)
Answer
Explanation:
Step1: Factor the numerator
We know that (a^{3}+b^{3}=(a + b)(a^{2}-ab + b^{2})), so (x^{3}+343=x^{3}+7^{3}=(x + 7)(x^{2}-7x + 49)). Then (k(x)=\frac{(x + 7)(x^{2}-7x + 49)}{x + 7}=x^{2}-7x + 49) for (x\neq - 7).
Step2: Calculate (k(x)) for each (x) - value
When (x=-7.1)
Substitute (x=-7.1) into (y=x^{2}-7x + 49). (y=(-7.1)^{2}-7\times(-7.1)+49=50.41 + 49.7+49 = 149.110)
When (x=-7.01)
Substitute (x=-7.01) into (y=x^{2}-7x + 49). (y=(-7.01)^{2}-7\times(-7.01)+49=49.1401+49.07 + 49=147.210)
When (x=-7.001)
Substitute (x=-7.001) into (y=x^{2}-7x + 49). (y=(-7.001)^{2}-7\times(-7.001)+49=49.0014001+49.007+49 = 147.008)
When (x=-6.999)
Substitute (x=-6.999) into (y=x^{2}-7x + 49). (y=(-6.999)^{2}-7\times(-6.999)+49=48.986001+48.993+49=146.979)
When (x=-6.99)
Substitute (x=-6.99) into (y=x^{2}-7x + 49). (y=(-6.99)^{2}-7\times(-6.99)+49=48.8601+48.93+49 = 146.790)
When (x=-6.9)
Substitute (x=-6.9) into (y=x^{2}-7x + 49). (y=(-6.9)^{2}-7\times(-6.9)+49=47.61+48.3+49=144.910)
Step3: Find the limit
As (x\to - 7), we can use the simplified function (k(x)=x^{2}-7x + 49). (\lim_{x\to - 7}k(x)=\lim_{x\to - 7}(x^{2}-7x + 49)=(-7)^{2}-7\times(-7)+49=49 + 49+49=147)
Answer:
| (x) | (k(x)) |
|---|---|
| (-7.1) | (149.110) |
| (-7.01) | (147.210) |
| (-7.001) | (147.008) |
| (-6.999) | (146.979) |
| (-6.99) | (146.790) |
| (-6.9) | (144.910) |
| (\lim_{x\to - 7}k(x)=147) |