Question

Find the derivative of the given functions from first principle: (x-1)(x-2)

Answer 1

hope this will help u... :-)

Answer 2

Answer:

2x - 3

Step-by-step explanation:

f(x) = (x-1)(x-2)

f'(x)  = Lim h - 0    ( f(x + h)  - f(x) )/ h

=> f'(x)  = Lim h - 0    ( (x + h - 1)(x + h - 2)  - (x-1)(x-2) )/ h

=> f'(x)  = Lim h - 0    ( (x + h - 1)(x + h - 2)  - (x-1)(x-2) )/ h

=> f'(x)  = Lim h - 0    ( (x + h)² - 3(x + h) + 2)  - (x² - 3x + 2 )/ h

=> f'(x)  = Lim h - 0    ( x² + h² + 2xh - 3(x + h) + 2)  - (x² - 3x + 2) )/ h

=> f'(x)  = Lim h - 0    ( h² + 2xh - 3h))/ h

=>  f'(x)  = Lim h - 0     h + 2x - 3

putting h = 0

=>  f'(x)  = 2x - 3