1. Graph: \( y=\frac{1}{2} x-3 \)

[b] If the straight line which represents the relation : \( X-2 y=a \) intersects \( y \)-axis at the point \( (b, 3) \), then find the value of each of \( a \) and \( b \)

2) Calculer puis écrire sans radical au dénominateur les expressions suivantes : \( C=\frac{\sqrt{3}}{\sqrt{3}+1}-\frac{\sqrt{3}-1}{\sqrt{3}+2}- \) et \( D=\left(\sqrt{5}+\frac{1}{\sqrt{5}}\right)^{2} \) 3) Soient \( x, y \) et \( z \) trois nombres réels strictement positifs. a) Montre que si \( x y+y z+x z=0 \) alors \( \frac{y+z}{x}+\frac{x+z}{y}+\frac{x+y}{z}=-3 \). b) Montrer que si \( x<y \) alors \( \sqrt{x+y+2 \sqrt{x y}}+\sqrt{x+y-2 \sqrt{x y}}=2 \sqrt{y} \) c) Montrer que si \( x \geq 2 \) alors \( (\sqrt{x+2 \sqrt{x-1}}+\sqrt{x-2 \sqrt{x-1}})^{2}=4(x-1) \)

if: \( x=\frac{5}{4} y \), what is \( \sqrt{x^{2}-y^{2}} \) \( \begin{array}{llll}\text { 1) } 1 & \text { 2)2 } & \text { 3) } 3 & 4) 4\end{array} \)

Ungkapkan fungsi kuadratik, \( f(x)=2 x^{2}+8 x+11 \) sebagai \( f(x)=a(x-h)^{2}+k \) di mana \( a, h \) dan \( k \) ialah pemalar. Kemudian lakarkan graf fungsi kuadratik tersebut. Sekiranya nilai a yang diperoleh menjadi lebih besar, nyatakan kesan perubahan tersebut terhadap bentuk dan kedudukan graf. Express the quadratic function, \( f(x)=2 x^{2}+8 x+11 \) as \( f(x)=a(x-h)^{2}+k \) where \( a, h \) and \( k \) are constants. Then sketch the graph of the quadratic function. If the obtained value of a becomes greater, state the effect of the change on the shape and position of the graph.

if: \( x=\frac{5}{4} f \), what is \( \sqrt{x^{r}-y^{r}}= \)