Final answer:
To express sin(x⁴) as an alternating series, substitute x⁴ for x in the Maclaurin series for sin(x) and simplify to get an alternating series with terms that include powers of x⁴ with alternating signs.
Step-by-step explanation:
We want to express sin(x⁴) as an alternating series using the Maclaurin series for the sine function. Recall that the Maclaurin series for the sine function is given by:
sin(x) = x - x³ / 3! + x⁵ / 5! - x⁹ / 7! + ... + (-1)²(n-1)/2 x²n-1 / (2n-1)! + ...
For sin(x⁴), we will substitute x⁴ for x in the Maclaurin series:
-
- Replace every instance of x with x⁴.
-
- Apply the substitution step by step to obtain the new series.
The new series becomes:
sin(x⁴) = x⁴ - (x⁴)³ / 3! + (x⁴)⁵ / 5! - (x⁴)⁹ / 7! + ... + (-1)²(n-1)/2 (x⁴)²n-1 / (2n-1)! + ...
As x⁴ is our only variable and there is no x in the final answer, we can simplify the series by evaluating the coefficients:
sin(x⁴) = x⁴ - x⁼ / 3! + x₀ / 5! - x₄ / 7! + ... + (-1)²(n-1)/2 x³(4n-4) / (2n-1)! + ...
This is an alternating series because the signs alternate between positive and negative for each consecutive term, and it follows the (-1)²(n-1)/2 pattern.