Question

The values of function f(x) at 5 discrete points are given below:

$x$	0	0.1	0.2	0.3	0.4
$f\left(x\right)$	0	15	60	135	240

$\text{Using trapezoidal rule step size of 0.1, the value of}{\int }_0^{0.4}f\left(x\right)dx\text{is \_\_\_\_\_\_\_.}$

• A. 33

Answer 1

The correct option is A 33
${\int }_0^{0.4}f\left(x\right)dx=\frac{h}{2}[y_0+2(y_1+y_2+y_3)+y_4]$

$=\frac{0.1}{2}[0+2(15+60+135)+240]$
$=33$