3 Diketahui ${f}^{\text{'}}\left(x\right)=3{x}^{2}$ , $f\left(1\right)=2$ , dan $f\left(2\right)=a$ , maka tentukan nilai dari $a$ ?

##### J A W A B
 ${f}^{\text{'}}\left(x\right)=3{x}^{2}$ $\to$ $f\left(x\right)={x}^{3}+c$ $f\left(1\right)=2$ $\to$ $f\left(1\right)={1}^{3}+c$ $2=1+c$ $c=1$ Jadi $f\left(x\right)={x}^{3}+1$ Dan $f\left(2\right)={2}^{3}+1$ $=9$