Final answer:
To find the derivatives of the function y = 8 / x⁴ - 4 / 9x² - 9x, use the power rule and quotient rule. The first derivative is -32 / x⁵ + (72x - 4)/(9x³). The second derivative is 160 / x⁶ - (216x² + 72) / (9x⁴). The third derivative is -960 / x⁷ + (864x⁴ - 432x) / (9x⁵). Substitute specific values of x to find Y(4) and Y(5).
Step-by-step explanation:
To find the derivatives of all orders of the function y = 8 / x⁴ - 4 / 9x² - 9x, we can use the power rule and the quotient rule.
First, let's find the first derivative, y'.
- Using the power rule, differentiate the first term: d/dx (8 / x⁴) = -32 / x⁵.
- Using the quotient rule, differentiate the second term: d/dx (-4 / 9x² - 9x) = (72x - 4)/(9x³).
- Combining the derivatives of both terms, we get: y' = -32 / x⁵ + (72x - 4)/(9x³).
Next, let's find the second derivative, y''.
- Differentiate y' using the power rule and quotient rule: y'' = d/dx (-32 / x⁵ + (72x - 4)/(9x³)) = 160 / x⁶ - (216x² + 72) / (9x⁴).
The third derivative, y''', can be found by differentiating y'' using the power rule and quotient rule: y''' = d/dx (160 / x⁶ - (216x² + 72) / (9x⁴)) = -960 / x⁷ + (864x⁴ - 432x) / (9x⁵).
To find Y(4) and Y(5), substitute x = 4 and x = 5 respectively in the original function y = 8 / x⁴ - 4 / 9x² - 9x. For any derivatives of order greater than 5, substitute the value of x in the corresponding derivative function.