Question

Derivative of the function $f(x)=(x-1)(x-2)$ is

• A. $2x+3$
• B. $3x-2$
• C. $3x+2$
• D. $2x-3$

Answer 1

Answer: (D)

Applying product rule,
$f^{\prime }(x)=(x-1)\frac{d}{dx}(x-2)+(x-2)\frac{d}{dx}(x-1)$
$=x-1+x-2=2x-3$