What is the remainder when x^4 + 36 is divided by x^2 + 8?

To find the remainder when the polynomial x4 + 36 is divided by x2 + 8, we can use polynomial long division or synthetic division. However, for many polynomial operations, a more straightforward approach is to express the dividend in a suitable form.

1. **Expressing the Dividend:** Start with:

x4 + 36

2. **Dividing Terms**: We know that x4 can be factored in terms of x2, as follows:

x4 = (x2)2

3. **Setting Up the Expression:** We want to rewrite x4 + 36 so we can separate it based on the divisor x2 + 8:

x4 + 36 = (x2 + 8)(x2 + A) + R

where A is some constant to be determined, and R will be the remainder we’re looking for.

4. **Polynomial Long Division:** Performing the division directly:

  • Divide the leading term of x4 by the leading term of x2, giving x2.
  • Multiply x2 by x2 + 8: x4 + 8x2.
  • Subtract this from x4 + 36:

(x4 + 36) – (x4 + 8x2 ) = 36 – 8x2

5. **Divide Again:** Now, take the result 36 – 8x2 and continue:

  • The highest degree term is now -8x2.
  • Divide -8x2 by x2, which gives -8.
  • Multiply -8 by x2 + 8:

Resulting in: -8x2 – 64

6. **Final Subtraction:** Subtract again:

(36 – 8x2}) – (-8x2 – 64) = 100

Thus, after performing this polynomial long division, we find that:

Remainder: 100

In summary, the remainder when x4 + 36 is divided by x2 + 8 is 100.

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