Answer :

Answer:

[tex]f'(x) = 2x-2[/tex]

Step-by-step explanation:

We are finding the derivative of the function:

[tex]f(x)=x^2-2x[/tex]

using the definition of the derivative:

[tex]\displaystyle f'(x) = \lim_{h\to0}\dfrac{f(x+h)-f(x)}{h}[/tex]

Plugging in the given function, we get:

[tex]\displaystyle f'(x) = \lim_{h\to0}\dfrac{[(x+h)^2-2(x+h)]-(x^2-2x)}{h}[/tex]

↓ expanding the numerator

[tex]\displaystyle f'(x) = \lim_{h\to0}\dfrac{[\not\!x^2+2hx + h^2-\not\!\!2x-2h]-\not\!x^2+\not\!\!2x}{h}[/tex]

↓ canceling opposite terms

[tex]\displaystyle f'(x) = \lim_{h\to0}\dfrac{h^2 + 2hx - 2h}{h}[/tex]

↓ factoring out an h from the numerator

[tex]\displaystyle f'(x) = \lim_{h\to0}\dfrac{\not \!h(h + 2x - 2)}{\not\!h}[/tex]

↓ canceling the h in the numerator and denominator

[tex]\displaystyle f'(x) = \lim_{h\to0}(h+2x-2)[/tex]

↓ evaluating the limit

[tex]\displaystyle f'(x) = 0+2x-2[/tex]

[tex]\displaystyle \boxed{f'(x) = 2x-2}[/tex]

Answer:

2(a + 1) + h

Step-by-step explanation:

I assume the expression is  [tex]\frac{f(a+h) - f(a)}{h}[/tex]

~~~~~~~~~~

[tex]\frac{f(a+h) - f(a)}{h}[/tex] = [tex]\frac{(a+h)^2 - 2(a+h) -a^2 +2a }{h}[/tex] =

[tex]\frac{a^2 +2ah + h^2 - 2a +2h - a^2 + 2a}{h}[/tex] =

[tex]\frac{2ah +h^2 +2h}{h}[/tex] = 2a + h + 2 = 2(a + 1) + h