Given
[tex]f(x)=\frac{3}{7}x^2+2x^3[/tex]You have to calculate f(1/2) to do so, replace the formula with x=1/2
[tex]f(\frac{1}{2})=\frac{3}{7}(\frac{1}{2})^2+2(\frac{1}{2})^3[/tex]Following the order of operations, you have to solve the exponents first, then the multiplications and finally the addition.
1) Solve the exponents
[tex]f(\frac{1}{2})=\frac{3}{7}\cdot\frac{1}{4}+2\cdot\frac{1}{8}[/tex]2) Solve the multiplications
[tex]\begin{gathered} f(\frac{1}{2})=\frac{3}{7}\cdot\frac{1}{4}+2\cdot\frac{1}{8} \\ f(\frac{1}{2})=\frac{3}{28}+\frac{1}{4} \end{gathered}[/tex]3) Solve the adition and simplify is necessary
[tex]\begin{gathered} f(\frac{1}{2})=\frac{3}{28}+\frac{1}{4}=\frac{3+7}{28} \\ f(\frac{1}{2})=\frac{10}{28}=\frac{5}{14} \end{gathered}[/tex]