Derivative of x^4 using Pascal’s Triangle and the limit definition with careful explanations!

Start with the limit definition of the derivative:
f'(x) = lim(h → 0) ((x + h)⁴ - x⁴) / h

Expand (x + h)⁴ using the binomial expansion from Pascal's Triangle:
(x + h)⁴ = x⁴ + 4x³h + 6x²h² + 4xh³ + h⁴

Substitute the expansion back into the limit definition:
f'(x) = lim(h → 0) (4x³h + 6x²h² + 4xh³ + h⁴) / h

Cancel out a factor of h from the numerator and denominator:
f'(x) = lim(h → 0) (4x³ + 6x²h + 4xh² + h³)

As h approaches 0, terms with h become 0:
f'(x) = 4x³
So, the derivative of x⁴ is 4x³.
1. x⁵: Here all five factors are x, so the exponents add up to 5.
2. 5x⁴h: Here four factors are x and one factor is h, so the exponents add up to 4 + 1 = 5.
3. 10x³h²: Here three factors are x and two factors are h, so the exponents add up to 3 + 2 = 5.
4. 10x²h³: Here two factors are x and three factors are h, so the exponents add up to 2 + 3 = 5.
5. 5xh⁴: Here one factor is x and four factors are h, so the exponents add up to 1 + 4 = 5.
6. h⁵: Here all five factors are h, so the exponents add up to 5.

Quiz: Understanding the Expansion of (x+h)ⁿ