The PDF is the derivative of your CDF. Use this fact to get started.
And you can either use your CDF or PDF to calculate part (b). (Think about what it is asking)
so would i just find the derivative of 1/8x + 3/16x^2 and plug in for F(b)-F(a)? In which case it would be 1/8 + 3/16x = 1/8 + 3/16(2) - 1/8+3/16(0)= 3/8?
so would i just find the derivative of 1/8x + 3/16x^2 and plug in for F(b)-F(a)? In which case it would be 1/8 + 3/16x = 1/8 + 3/16(2) - 1/8+3/16(0)= 3/8?
The derivative of $\displaystyle F(x)$ is the density.
The probability $\displaystyle P(a<X<b)=F(b)-F(a)$