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CS 1410 Programming Assignment #1
C++ Operators and Statements
Program #1
Quadratic equations have the form: ax2 + bx + c = 0 where a (cannot be 0), b, and c are
the coefficients and x is the unknown value. x is computed using the quadratic formula:
xbb ac
a
=
−± −
2
4
2
There are some complex issues (a poor pun BTW) that must be dealt with but these are best left
until the next chapter. The ± operation leads to two similar calculations: replace ‘±’ with ‘+’ in
the first calculation and with ‘-’ in the second. The two calculations produce two roots or
solutions to the original equation.
The math library includes a function named sqrt to calculate square roots. Any program that
uses this function must include the math header file (the library is linked automatically).
#include <cmath>
. . .
y = sqrt(x);
Note that x in the above function may be a constant, a variable, or an expression.
Write a program named roots.cpp that:
1. prompts for and reads the coefficients into double variables in the order a, b, and c
2. calculates and prints two roots
Program #2
Write a program named cone.cpp that:
1. prompts for and reads (in this order) a radius and a height
2. calculates and prints the volume of a right cone:
vrh
=
1
3
2
π
3. calculates and prints the total surface area (base + cone):
Sr rrh
=+ +
ππ
222
The math header file <cmath> defines a symbolic constant for π: M_PI (which you should use).
The Microsoft compiler requires a non-standard definition before math constants may be used:
#define _USE_MATH_DEFINES // Microsoft only
#include <iostream>
#include <cmath>
using namespace std;
You may use the pow function (included in the math library and demonstrated in class) to square
the values in the above formulas; however, for squares and cubes, it’s just about as easy to
multiply the numbers by themselves: radius * radius.
