Question

If `int_0^alpha3x^2dx=8` then the value of α is :

(a) 0

(b) -2

(c) 2 

(d) ±2

Answer 1

(c)

`int_0^alpha3x^2dx=8`

⇒ `[(3x^3)/3]_0^alpha=8`

⇒ `[x^3]_0^alpha=8`

⇒ α³=8

∴ α = 2