Originally Posted by
creatively12 A straight line y=4x+1 has area under it between x=1 and x=3,
Find the area using
a) the formula for the area of trapezium
$\displaystyle b_1 = y(1)$ , $\displaystyle b_2 = y(3)$ , $\displaystyle h = 3-1 = 2$
$\displaystyle A = \frac{h}{2}(b_1+b_2)$
b) using integration
$\displaystyle A = \int_1^3 4x+1 \, dx$