Find the indicated terms in each of the sequences in Questions 7 to 10 whose nth term are :
`a_(n)=(-1)^(n-1)n^(3),a_(9)`

Explanation

To find the 9th term of the sequence defined by the nth term \( a_n = (-1)^{n-1} n^3 \), we will follow these steps:

### Step 1: Identify the formula for the nth term
The formula for the nth term is given as:
\[ a_n = (-1)^{n-1} n^3 \]

### Step 2: Substitute \( n = 9 \) into the formula
To find the 9th term, we substitute \( n = 9 \) into the formula:
\[ a_9 = (-1)^{9-1} \cdot 9^3 \]

### Step 3: Simplify the exponent
Calculate the exponent:
\[ 9 - 1 = 8 \]
Thus, we have:
\[ a_9 = (-1)^8 \cdot 9^3 \]

### Step 4: Evaluate \( (-1)^8 \)
Since \( (-1)^{\text{even}} = 1 \):
\[ (-1)^8 = 1 \]
So, we can simplify:
\[ a_9 = 1 \cdot 9^3 \]

### Step 5: Calculate \( 9^3 \)
Now, we need to calculate \( 9^3 \):
\[ 9^3 = 9 \times 9 \times 9 = 81 \times 9 = 729 \]

### Step 6: Final result
Thus, the 9th term \( a_9 \) is:
\[ a_9 = 729 \]

### Conclusion
The required answer is:
\[ \boxed{729} \]