Express each of the following in the form b or bi, where b is a real number
`i(-i)`

Answer

To express the expression \( i(-i) \) in the form \( b \) or \( bi \), where \( b \) is a real number, we can follow these steps:

### Step 1: Write the expression
Start with the expression:
\[ i(-i) \]

### Step 2: Simplify the expression
Multiply \( i \) and \( -i \):
\[ i(-i) = -i^2 \]

### Step 3: Substitute the value of \( i^2 \)
We know that \( i^2 = -1 \). Substitute this value into the expression:
\[ -i^2 = -(-1) \]

### Step 4: Simplify further
This simplifies to:
\[ -(-1) = 1 \]

### Final Result
Thus, the expression \( i(-i) \) can be expressed as:
\[ 1 \]

This is in the form \( b \) where \( b = 1 \).

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