$a)$  

$f\left(x\right)=x^2$  

$g\left(x\right)=2x^2$  

$h\left(x\right)=3x^2$  

$f\left(-\frac{1}{2}\right)={\left(-\frac{1}{2}\right)}^2=\frac{1}{4}$  

$f\left(\frac{\sqrt{2}}{2}\right)={\left(\frac{\sqrt{2}}{2}\right)}^2=\frac{2}{4}=\frac{1}{2}$ $f\left(\frac{\sqrt{2}}{2}\right)={\left(\frac{\sqrt{2}}{2}\right)}^2=\frac{2}{4}=\frac{1}{2}$  

$g\left(x\right)=2f\left(x\right)$  

$g\left(-\frac{1}{2}\right)=2f\left(-\frac{1}{2}\right)=\frac{2}{4}=\frac{1}{2}$  

$g\left(\frac{\sqrt{2}}{2}\right)=2f\left(\frac{\sqrt{2}}{2}\right)=1$  

$h\left(x\right)=3f\left(x\right)$  

$h\left(-\frac{1}{2}\right)=3f\left(-\frac{1}{2}\right)=\frac{3}{4}$  

$h\left(\frac{\sqrt{2}}{2}\right)=3f\left(\frac{\sqrt{2}}{2}\right)=\frac{3}{2}$     

      

 

$b)$  

$f\left(x\right)=-x^2$  

$g\left(x\right)=-\frac{1}{2}{x}^2$  

$h\left(x\right)=-4x^2$          

$f\left(-\frac{1}{2}\right)=-\frac{1}{4}$  

$f\left(\frac{\sqrt{2}}{2}\right)=-\frac{2}{4}=-\frac{1}{2}$  

$g\left(-\frac{1}{2}\right)=-\frac{1}{2}\cdot \frac{1}{4}=-\frac{1}{8}$  

$g\left(\frac{\sqrt{2}}{2}\right)=-\frac{1}{2}\cdot \frac{2}{4}=-\frac{1}{4}$  

$h\left(-\frac{1}{2}\right)=-4\cdot \frac{1}{4}=-1$  

$h\left(\frac{\sqrt{2}}{2}\right)=-4\cdot \frac{1}{2}=-2$