$5-f(x)=\frac{sinx}{cosx}$ is given, find $f^{\text{'}}(0)($Hint: $si{n}^2(x)+co{s}^2(x)=1)$

$6-$ Find the limit $\underset{x}{lim}\frac{6x^2+5x-1}{2x^2+5}$

$7-f(x)=\frac{1}{2}{x}^3+2x^2+\frac{1}{\sqrt[\phantom{2}]{x}}-5x+4$ is given, Find $f^{\text{'}}(x)$

$8-$ Find the limit of $\underset{x1}{lim}\frac{x-1}{\sqrt[\phantom{2}]{x+3}-2}$

$9-$ If $f(x)=(x^2+3x-9{)}^{15},$ find $f^{\text{'}}(2)$

$10-$ If $\sqrt[\phantom{2}]{x^2+5x-1}+\sqrt[\phantom{2}]{x-4},$ then find $f^{\text{'}}(5)$