marks$)$ Write a MATLAB

$3k^2$ for $k=1,2,3,$dots,$20.$

$4$ marks$)$ Write a MATLAB $($M$-)$ script file that uses a for$-$loop and if$-$elseif$-$else structure to plot the function

$y(x)=\{\begin{array}{cc}\sqrt[\phantom{2}]{x^2+1},& x<mn>0</mn>\\ 3x+1,& 0x<mn>1</mn><mn>0</mn>\\ 9sin(5x-50)+31,& x10\end{array}$

or $x$ spanning from $-5$ to $15$ with steps of $0\mathrm{.}01.$ Use appropriate labels on your $x-$axis and $y-$axis. Show the

esulting plot. Hint: create a for$-$loop that steps an index i through all values of $x(i)$ while solving for values of $y(i).$

$(0\mathrm{.}3$ marks$)$ Answer the following questions about base$-10$ representations.

Given an eight$-$digit base$-10($decimal$)$ computer system, a floating point number can be represented by one

mantissa sign digit, four mantissa digits, one exponent sign digit, and two exponent digits. Express the floating

point presentation in terms of base$-10$ exponential number format with mantissa and exponent; state the largest

and smallest positive values, and the machine precision for the eight$-$digit computer system.