Notation of the efforts at the joints for the flexion of a beam: <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle R_{A}}"><semantics><mrow class="MJX-TeXAtom-ORD"><mstyle displaystyle="true" scriptlevel="0"><msub><mi>R</mi><mrow class="MJX-TeXAtom-ORD"><mi>A</mi></mrow></msub></mstyle></mrow><annotation encoding="application/x-tex">{\displaystyle R_{A}}</annotation></semantics></math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/0b096f1c60d7fdc543f3bc583fe32601f1c2f0cf" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.671ex; width:3.229ex; height:2.509ex;" alt="{\displaystyle R_{A}}"></span> for a strength and <span class="mwe-math-element"><span class="mwe-math-mathml-inline mwe-math-mathml-a11y" style="display: none;"><math xmlns="http://www.w3.org/1998/Math/MathML" alttext="{\displaystyle M_{A}}"><semantics><mrow class="MJX-TeXAtom-ORD"><mstyle displaystyle="true" scriptlevel="0"><msub><mi>M</mi><mrow class="MJX-TeXAtom-ORD"><mi>A</mi></mrow></msub></mstyle></mrow><annotation encoding="application/x-tex">{\displaystyle M_{A}}</annotation></semantics></math></span><img src="https://wikimedia.org/api/rest_v1/media/math/render/svg/a272f700c41b9a2ff645309108b67bde9f3a132f" class="mwe-math-fallback-image-inline" aria-hidden="true" style="vertical-align: -0.671ex; width:3.719ex; height:2.509ex;" alt="{\displaystyle M_{A}}"></span> for a moment at the joint A.
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