Q. If the area bounded by the $x$-axis, the curve $y = f(x)$ and lines $x = a$ and $x = b$ is independent of $b,\ \forall\ b > a$ ($a$ is a constant), then $f$ is

A) The zero function
B) The identity function
C) A non-zero constant function
D) None of the above
Explanation

(a)
According to the given condition
$\int_{a}^{b}{f(x)dx = c}$
On differentiating $w.r.t.b$, we get
$f(b) = 0\ \Rightarrow \ f(x) = 0$

Dr. Abubacker
Reviewed by Dr. Abubacker

Physics Educator & NEET/JEE Specialist

Ph.D. in Physics with 19+ years of teaching experience.