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Module DEMO-32-89DEMO-C-32

Quadratic Equation Positive Root

DEMO-C-32 • Programming in C

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Problem Statement

Calculate the positive root of a quadratic equation ax^2 + bx + c = 0.

Formula: (-b + sqrt(b^2 - 4ac)) / (2a).

Target difficulty: Medium

Constraints

b^2 - 4ac >= 0, a != 0

Input Format

Three floating-point numbers a b c.

Output Format

The positive root formatted to 2 decimal places.

Sample Testcases

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Sample #1
Public sample
Input
1 -3 2
Output
2.00
Explanation
(-(-3.0) + sqrt(-3.0^2 - 41.02.0)) / (2*1.0) = 2.00
Sample #2
Public sample
Input
1 2 1
Output
-1.00
Explanation
(-(2.0) + sqrt(2.0^2 - 41.01.0)) / (2*1.0) = -1.00
Sample #3
Public sample
Input
1 -7 12
Output
4.00
Explanation
(-(-7.0) + sqrt(-7.0^2 - 41.012.0)) / (2*1.0) = 4.00
Sample #4
Public sample
Input
1 0 -9
Output
3.00
Explanation
(-(0.0) + sqrt(0.0^2 - 41.0-9.0)) / (2*1.0) = 3.00

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