Answer:
(-5, 0) ∪ (5, ∞)
Step-by-step explanation:
I find a graph convenient for this purpose. (See below)
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When you want to find where a function is increasing or decreasing, you want to look at the sign of the derivative. Here, the derivative is ...
f'(x) = 4x^3 -100x = 4x(x^2 -25) = 4x(x +5)(x -5)
This has zeros at x=-5, x=0, and x=5. The sign of the derivative will be positive when 0 or 2 factors have negative signs. The signs change at the zeros. So, the intervals of f' having a positive sign are (-5, 0) and (5, ∞).
9514 1404 393
Answer:
1. proportional, 6
2. not proportional
Step-by-step explanation:
<u>Table 1</u>
Each y-value is 6 times the corresponding x-value, so the variables are proportional, and y = 6 times x.
<u>Table 2</u>
The ratios of y to x are 2, 4, 8, so are not the same. The values are not proportional.
One form of the relation of inverse variation is y = k/x.
first step: Find the value of k: Taking the values x=5 and y = 4, 4=k/5, or k=20. Then, y = 20/x.
Next: Let y = 7 and find the corresp. value of x: 7=20/x, or 7x=20, or
x = 20/7 (answer)
Answer:
hope you understood my handwriting