Mathematics · Differential Equations

Control-System Phase Margin instability phase boundary in degrees Solver

Rearrange the control-system phase margin relationship and solve for instability phase boundary in degrees.

Runs locally
Your numbers

Inputs and results stay in this browser. Change one value at a time to explore the relationship.

Your inputCalculatedPassed forward in chains
instability phase boundary in degrees-180
Reconstructed phase margin-45

Calculation steps

  1. Use a=c+b with phase margin=-45 and open-loop phase at gain crossover in degrees=-135.
  2. instability phase boundary in degrees=-180.
  3. Substitution into c=a−b reconstructs -45.

Understand Control-System Phase Margin: solve instability phase boundary in degrees

One idea, three depths

Choose how deeply to explain Control-System Phase Margin: solve instability phase boundary in degrees

Control-System Phase Margin: solve instability phase boundary in degrees: Rearrange the control-system phase margin relationship and solve for instability phase boundary in degrees.

Age 5Explain it to a 5-year-oldStart with a picture

Imagine using Control-System Phase Margin: solve instability phase boundary in degrees to answer this question: rearrange the control-system phase margin relationship and solve for instability phase boundary in degrees? Enter phase margin and open-loop phase at gain crossover in degrees; the calculator shows instability phase boundary in degrees. For example: instability phase boundary in degrees=-180 and open-loop phase at gain crossover in degrees=-135 produce phase margin=-45. The answer tells you instability phase boundary in degrees.

Age 15Explain it to a 15-year-oldConnect it to the formula

Under the standard negative-feedback convention, phase margin is the instability boundary minus the open-loop phase at gain crossover. This page isolates instability phase boundary in degrees and verifies it in the original relationship. The rule is a=c+b. Its input values are phase margin, open-loop phase at gain crossover in degrees, and the main result is instability phase boundary in degrees. For example: instability phase boundary in degrees=-180 and open-loop phase at gain crossover in degrees=-135 produce phase margin=-45.

CollegeExplain it at college levelState the model precisely

This calculator evaluates the stated control-system phase margin: solve instability phase boundary in degrees relation over the valid real-number domain stated below. The implemented relation is a=c+b, evaluated from phase margin, open-loop phase at gain crossover in degrees to produce instability phase boundary in degrees. Under the standard negative-feedback convention, phase margin is the instability boundary minus the open-loop phase at gain crossover. This page isolates instability phase boundary in degrees and verifies it in the original relationship. Sign and wrapping conventions can reverse the displayed subtraction; report the convention explicitly.

Inputs and valid domain

  • phase margin must be a finite real number.
  • open-loop phase at gain crossover in degrees must be a finite real number.

Important boundary: Sign and wrapping conventions can reverse the displayed subtraction; report the convention explicitly.

The formula

a=c+b

How the calculator works through it

It substitutes phase margin, open-loop phase at gain crossover in degrees into the formula and exposes every numerical step above. The main output is instability phase boundary in degrees, accompanied by Reconstructed phase margin.

Read the result correctly

The instability phase boundary in degrees is the direct answer to “rearrange the control-system phase margin relationship and solve for instability phase boundary in degrees.” Read it with the units shown beside the inputs; a sign, angle, percentage or rate changes what the number means.

A worked check

instability phase boundary in degrees=-180 and open-loop phase at gain crossover in degrees=-135 produce phase margin=-45.

Where this model stops being reliable

Sign and wrapping conventions can reverse the displayed subtraction; report the convention explicitly.

Learn it by changing one value

Begin with the worked example, then change one value while keeping the others fixed. Compare the new result and calculation steps to identify which part of the formula changed.

Dictionary terms behind this calculator

Before studying the codeWhat you should know firstUse the calculator immediately, or check the foundations before reading the implementation.

These foundations help you understand why Control-System Phase Margin: solve instability phase boundary in degrees works. They never block the calculator, and “optional” means useful context rather than a hidden requirement.

Hard requirements

  • Reading formulas and substituting values

    Control-System Phase Margin: solve instability phase boundary in degrees uses a=c+b. You need to recognise what each side represents before substituting the stated inputs or rearranging the relationship.

    Review this foundation about 4 min

Strong support

  • Derivatives and changing systems

    A derivative describes the changing quantity that Control-System Phase Margin: solve instability phase boundary in degrees models or approximates.

    Review this foundation about 7 min

Optional enrichment

  • Exponential solution behaviour

    Exponential behaviour helps you recognise common growth, decay and response patterns related to Control-System Phase Margin: solve instability phase boundary in degrees.

    Review this foundation about 7 min
Learn the missing foundationsI already know these — show the code

Mathematics → algorithm → program

Implement this calculation in code

These are direct reference implementations of the calculator's principal relationship and first output. They run locally and include a small known-answer check where the language supports it.

Algorithm

  1. Read phase margin, open-loop phase at gain crossover in degrees.
  2. Evaluate the principal relationship: a=c+b.
  3. Return instability phase boundary in degrees and check the domain conditions described above.
Python
            from math import *

def control_phase_margin_solve_a(c, b) -> float:
    return (c + b)

assert abs(control_phase_margin_solve_a(-45, -135) - -180) < 1e-6 * max(1.0, abs(-180))
          
Current calculator valuesUpdates when you change an input above.
              
            
C
            #include <assert.h>
#include <math.h>

double control_phase_margin_solve_a(double c, double b) {
    return (c + b);
}

int main(void) {
    const double expected = -180;
    const double actual = control_phase_margin_solve_a(-45, -135);
    assert(fabs(actual - expected) < 1e-6 * fmax(1.0, fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
C++
            #include <cassert>
#include <cmath>
#include <numbers>

double control_phase_margin_solve_a(double c, double b) {
    return (c + b);
}

int main() {
    constexpr double expected = -180;
    const double actual = control_phase_margin_solve_a(-45, -135);
    assert(std::fabs(actual - expected) < 1e-6 * std::fmax(1.0, std::fabs(expected)));
}
          
Current calculator valuesUpdates when you change an input above.
              
            
Linux x86-64 assembly

x86-64 NASM · System V ABI · Linux · SSE2 with libm where required

            ; double control_phase_margin_solve_a(double c, double b)
; Linux x86-64 NASM · System V ABI · first eight doubles in xmm0–xmm7
global control_phase_margin_solve_a
section .text

control_phase_margin_solve_a:
    push rbp
    mov rbp, rsp
    sub rsp, 32
    movsd [rbp-8], xmm0
    movsd [rbp-16], xmm1
    movsd xmm0, [rbp-8]
    addsd xmm0, [rbp-16]
    movsd [rbp-24], xmm0
    movsd xmm0, [rbp-24]
    leave
    ret
          
Current calculator valuesUpdates when you change an input above.
              
            
MATLAB
            function result = control_phase_margin_solve_a(c, b)
    result = (c + b);
end
          
Current calculator valuesUpdates when you change an input above.
              
            
Wolfram Language
            ClearAll[mwCalculate];
mwCalculate[c_, b_] := (c + b);
          
Current calculator valuesUpdates when you change an input above.
              
            

Continue in mathematical software

The downloaded file includes your current inputs and first calculated result. It is created locally.

Floating-point answers can differ slightly by language, compiler and processor. Compare within a suitable tolerance rather than assuming every decimal representation will be identical.

Supporting sourcesAcademic referencesPrimary standards, textbooks and complete citations

Standards, reading and academic references

Use the calculator as the worked interaction, then consult the primary standards and academic textbooks listed below. MW SysArc links to the original sources; the explanation on this page is original and does not reproduce them.

Calculus Volume 1

Read OpenStax Calculus: Derivatives and integration
Cite this book
APA 7
Strang, G., & Herman, E. (2016). Calculus volume 1. OpenStax. https://openstax.org/books/calculus-volume-1/pages/1-introduction
MLA 9
Strang, Gilbert, and Edwin Herman. Calculus Volume 1. OpenStax, 2016, https://openstax.org/books/calculus-volume-1/pages/1-introduction.
Chicago author-date
Strang, Gilbert, and Edwin Herman. 2016. Calculus Volume 1. Houston, TX: OpenStax. https://openstax.org/books/calculus-volume-1/pages/1-introduction.

OpenStax entries are free to read online. Follow the licence shown on each linked source before redistributing or adapting its content.

Reuse the page responsiblyCite this pageAPA, MLA, Chicago, Harvard, BibTeX and RIS

These formats cite this calculator page itself. They are separate from the academic references above, which support the mathematical method and terminology.

APA 7

MW SysArc. (2026, July 21). Control-System Phase Margin instability phase boundary in degrees Solver. MW SysArc Tools. https://math.mwsysarc.com/differential-equations/control-phase-margin-instability-phase-boundary-in-degrees-solver

MLA 9

MW SysArc. “Control-System Phase Margin instability phase boundary in degrees Solver.” MW SysArc Tools, 21 July 2026, https://math.mwsysarc.com/differential-equations/control-phase-margin-instability-phase-boundary-in-degrees-solver. Accessed 31 Aug. 2026.

Chicago 17

MW SysArc. “Control-System Phase Margin instability phase boundary in degrees Solver.” MW SysArc Tools. Published July 21, 2026. Accessed August 31, 2026. https://math.mwsysarc.com/differential-equations/control-phase-margin-instability-phase-boundary-in-degrees-solver.

Harvard

MW SysArc (2026) ‘Control-System Phase Margin instability phase boundary in degrees Solver’, MW SysArc Tools. Published 21 July 2026. Available at: https://math.mwsysarc.com/differential-equations/control-phase-margin-instability-phase-boundary-in-degrees-solver (Accessed: 31 August 2026).

BibTeX and RIS records

BibTeX

@misc{mwsysarc_control_phase_margin_solve_a_2026,
  author = {{MW SysArc}},
  title = {Control-System Phase Margin instability phase boundary in degrees Solver},
  howpublished = {MW SysArc Tools},
  year = {2026},
  url = {https://math.mwsysarc.com/differential-equations/control-phase-margin-instability-phase-boundary-in-degrees-solver},
  note = {Published July 21, 2026; accessed August 31, 2026}
}

RIS

TY  - ELEC
AU  - MW SysArc
TI  - Control-System Phase Margin instability phase boundary in degrees Solver
T2  - MW SysArc Tools
PY  - 2026
DA  - 2026-07-21
Y2  - 2026-08-31
UR  - https://math.mwsysarc.com/differential-equations/control-phase-margin-instability-phase-boundary-in-degrees-solver
N1  - Published July 21, 2026
ER  -

Clear answers

Frequently asked questions

What does the Control-System Phase Margin: solve instability phase boundary in degrees do?

Rearrange the control-system phase margin relationship and solve for instability phase boundary in degrees.

How does the Control-System Phase Margin: solve instability phase boundary in degrees work?

The calculator applies a=c+b. Under the standard negative-feedback convention, phase margin is the instability boundary minus the open-loop phase at gain crossover. This page isolates instability phase boundary in degrees and verifies it in the original relationship.

What can I learn from the Control-System Phase Margin: solve instability phase boundary in degrees?

It connects the mathematical rule to your chosen numbers and shows each calculation step. Change one input at a time to see how the result responds.

Does MW SysArc receive or store what I enter?

No. The calculation runs locally in your browser. MW SysArc does not receive or store your calculation inputs.

How should I use the result?

Use the steps to understand the method, then verify important school or professional work using the notation and rounding rules required in your setting.

Last reviewed . Calculations tested .

MW SysArc Certified