Fig 1 shows skectches of the curve
y = 3x^2 + k

The area of A is 3 times the area of B, Find the value of K.

2. I think it goes:

Integrate 3x^2+k and you get: x^3 + kx

Now we know A = 3B so using the integral above we get:

A as 8 + 2k, and
B as 1 + k

so 8 + 2k = 3(1 + k)

Which gives k = 5

3. Thanks.