Specifications

Overview: You will write two programs this week. The first will find the result of a specified

expression after reading input values for x and y$,$ and the second will calculate the integral number of

units $($acres$,$ square yards, and square feet$)$ in a specified number of square inches.

$$ Expression.java

Requirements: A program is needed that inputs values of type double for x and y and solves for

the result of the indicated expression when xy is not equal to zero. If xy is equal to zero, then the

result is zero.

Design: The result should be calculated as follows $($except for the special case$)$:

$=(10+32\mathrm{.}6)(51\mathrm{.}567)$

$$ for $!=0$

Note: if xy is $0,$ then result is undefined.

Three examples of program output for the indicated input values are shown below. Note that

lines $2$ and $3$ for the input values begin with tab which is equivalent to three spaces in jGRASP

$($i$.$e$.,$ your program should use the $\backslash$t escape sequence for a tab$).$

Example #$1$

Line # Program output

$1$

$2$

$3$

$4$

$5$

$----$jGRASP exec: java Expression

result $=(10$x $+32\mathrm{.}6)(5$y $-1\mathrm{.}567)/$ xy

x $=1\mathrm{.}5$

y $=3\mathrm{.}1$

result $=142\mathrm{.}62597849462367$

$----$jGRASP: operation complete.

Project: Variables and Expressions Page $2$ of $3$

Page $2$ of $3$

Example #$2$

Line # Program output

$1$

$2$

$3$

$4$

$5$

$----$jGRASP exec: java Expression

result $=(10$x $+32\mathrm{.}6)(5$y $-1\mathrm{.}567)/$ xy

x $=0\mathrm{.}0$

y $=34\mathrm{.}7$

result is "undefined"

$----$jGRASP: operation complete.

Example #$3$

Line # Program output

$1$

$2$

$3$

$4$

$5$

$----$jGRASP exec: java Expression

result $=(10$x $+32\mathrm{.}6)(5$y $-1\mathrm{.}567)/$ xy

x $=12\mathrm{.}5$

y $=0$

result is "undefined"

$----$jGRASP: operation complete.

Example #$4$

Line # Program output

$1$

$2$

$3$

$4$

$5$

$----$jGRASP exec: java Expression

result $=(10$x $+32\mathrm{.}6)(5$y $-1\mathrm{.}567)/$ xy

x $=-1\mathrm{.}5$

y $=-6\mathrm{.}2$

result $=-61\mathrm{.}632172043010755$

$----$jGRASP: operation complete.

Code: Your numeric variables should be of type double. Use an if$-$else statement to determine if

the divisor in the expressions is zero. Note that the value of x is zero in Example #$2$ and that the

value of y is zero in Example #$3,$ which means the divisor, xy$,$ is zero each case and result is

undefined.

Test: You are responsible for testing your program, and it is important to not rely only on the

examples above. Remember that the input values are doubles, so be sure to test both positive and

negative values $($with and without a decimal point$)$ for x and y$.$ You should use a calculator or

jGRASP interactions to check your answers.

$$ SquareUnits.java

Requirements: A surveyor requires a program that allows the user to enter a value in square

inches and then displays the combination of acres, square yards, square feet, and square inches so

that each value is maximized in order by acres, square yards, square feet, and finally square

inches. The input value should not exceed $1,000,000,000$ square inches. You can assume the user

will always enter a non$-$negative value; however, negative values will also work.