// Numbas version: exam_results_page_options {"name": "Power Rule, Sum or Difference (Instructional)", "metadata": {"description": "

Fairly simple questions using differentiation \"power rule\" and \"sum or difference rules\" to differentiate single term functions and polynomials.

\n

Some co-efficients and indices can be negative and/or fractional.

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Simple application of \"Power Rule\" to differentiate single term functions.

\n

All co-efficients and powers are integer (though some may be negative.

", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "

The Power Rule

\n

You can find the derivative for powers of functions using the following rule:

\n

If   \\( y=ax^n \\)  then   \\( \\frac{dy}{dx} = n \\times a x^{n-1} \\) 

\n

The Sum or Difference Rules

\n

The derivative of   \\( f(x) + g(x) \\)  is  \\(  \\frac{df}{dx} + \\frac{dg}{dx} \\)          and          the derivative of   \\( f(x) - g(x) \\)  is  \\(  \\frac{df}{dx} - \\frac{dg}{dx} \\)

\n

", "advice": "

We are asked to differentiate a variety of functions, each consisting of a single term.

\n

We can do this using the \"Power Rule\" for differentiation:

\n

If   \\( y=ax^n \\)  then   \\( \\frac{dy}{dx} = n \\times a x^{n-1} \\)

\n

In plain language, \"multiply by the power, then reduce the power by one\".

\n

Then:

\n

a)

\n

\\( y= \\var{a_1} x^{\\var{n_1}} \\)

\n

\\( \\frac{dy}{dx } = \\var{n_1} \\times \\var{a_1} x^{\\var{n_1} - 1}                  \\)

\n

\\( \\frac{dy}{dx } = \\simplify{ {n_1}*{a_1}*x^{{n_1} - 1} } \\)

\n

\n

b)

\n

\\( y= \\var{a_2} x^{\\var{n_2}} \\)

\n

\\( \\frac{dy}{dx } = \\var{n_2} \\times \\var{a_2} x^{\\var{n_2} - 1}                  \\)

\n

\\( \\frac{dy}{dx } = \\simplify{ {n_2}*{a_2}*x^{{n_2} - 1} } \\)

\n

c)

\n

\\( y= \\var{a_3} x^{\\var{n_3}} \\)

\n

\\( \\frac{dy}{dx } = \\var{n_3} \\times \\var{a_3} x^{\\var{n_3} - 1}                  \\)

\n

\\( \\frac{dy}{dx } = \\simplify{ {n_3}*{a_3}*x^{{n_3} - 1} } \\)

\n

 

\n

 

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Co-efficient for Q1

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Differentiate the following:

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\\( y= \\var{a_1} x^{\\var{n_1}} \\)

\n

\\( \\frac{dy}{dx } = \\)[[0]]

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\\( y= \\var{a_2} x^{\\var{n_2}} \\)

\n

\\( \\frac{dy}{dx } = \\) [[0]]

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\\( y= \\var{a_3} x^{\\var{n_3}} \\)

\n

\\( \\frac{dy}{dx } = \\)  [[0]]

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Simple application of \"Power Rule\" to differentiate single term functions.

\n

Some co-efficients and powers are non-integer and some may be negative.

", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "

The Power Rule

\n

You can find the derivative for powers of functions using the following rule:

\n

If   \\( y=ax^n \\)  then   \\( \\frac{dy}{dx} = n \\times a x^{n-1} \\) 

\n

The Sum or Difference Rules

\n

The derivative of   \\( f(x) + g(x) \\)  is  \\(  \\frac{df}{dx} + \\frac{dg}{dx} \\)          and          the derivative of   \\( f(x) - g(x) \\)  is  \\(  \\frac{df}{dx} - \\frac{dg}{dx} \\)

\n

", "advice": "

We are asked to differentiate a variety of functions, each consisting of a single term.

\n

We can do this using the \"Power Rule\" for differentiation:

\n

If   \\( y=ax^n \\)  then   \\( \\frac{dy}{dx} = n \\times a x^{n-1} \\)

\n

In plain language, \"multiply by the power, then reduce the power by one\".

\n

Then:

\n

a)

\n

\\( y= \\var{a_1} x^{\\var{n_1}} \\)

\n

\\( \\frac{dy}{dx } = \\var{n_1} \\times \\var{a_1} x^{\\var{n_1} - 1}                  \\)

\n

\\( \\frac{dy}{dx } = \\simplify{ {n_1}*{a_1}*x^{{n_1} - 1} } \\)

\n

\n

b)

\n

\\( y= \\var{a_2} x^{\\var[fractionNumbers]{n_2}} \\)

\n

\\( \\frac{dy}{dx } = \\var{n_2} \\times \\var{a_2} x^{\\var[fractionNumbers]{n_2} - 1}                  \\)

\n

\\( \\frac{dy}{dx } = \\simplify{ {n_2}*{a_2}*x^{{n_2} - 1} } \\)

\n

c)

\n

\\( y= \\var{a_3} x^{\\var{n_3}} \\)

\n

\\( \\frac{dy}{dx } = \\var{n_3} \\times \\var{a_3} x^{\\var{n_3} - 1}                  \\)

\n

\\( \\frac{dy}{dx } = \\simplify{ {n_3}*{a_3}*x^{{n_3} - 1} } \\)

\n

 

\n

 

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Co-efficient for Q1

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List to allow random selection of fractional powers

", "templateType": "list of numbers", "can_override": false}}, "variablesTest": {"condition": "", "maxRuns": 100}, "ungrouped_variables": ["a_1", "n_1", "a_2", "n_2", "a_3", "n_3", "fractional_powers"], "variable_groups": [], "functions": {}, "preamble": {"js": "", "css": ""}, "parts": [{"type": "information", "useCustomName": false, "customName": "", "marks": 0, "scripts": {}, "customMarkingAlgorithm": "", "extendBaseMarkingAlgorithm": true, "unitTests": [], "showCorrectAnswer": true, "showFeedbackIcon": true, "variableReplacements": [], "variableReplacementStrategy": "originalfirst", "nextParts": [], "suggestGoingBack": false, "adaptiveMarkingPenalty": 0, "exploreObjective": null, "prompt": "

Differentiate the following:

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\\( y= \\var{a_1} x^{\\var{n_1}} \\)

\n

\\( \\frac{dy}{dx } = \\)[[0]]

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\\( y= \\var{a_2} x^{\\var[fractionNumbers]{n_2}} \\)

\n

\\( \\frac{dy}{dx } = \\) [[0]]

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\\( y= \\var{a_3} x^{\\var{n_3}} \\)

\n

\\( \\frac{dy}{dx } = \\)  [[0]]

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Simple application of \"Power Rule\" to differentiate polynomials.

\n

Some co-efficients and powers are non-integer and some may be negative.

", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "

The Power Rule

\n

You can find the derivative for powers of functions using the following rule:

\n

If   \\( y=ax^n \\)  then   \\( \\frac{dy}{dx} = n \\times a x^{n-1} \\) 

\n

The Sum or Difference Rules

\n

The derivative of   \\( f(x) + g(x) \\)  is  \\(  \\frac{df}{dx} + \\frac{dg}{dx} \\)          and          the derivative of   \\( f(x) - g(x) \\)  is  \\(  \\frac{df}{dx} - \\frac{dg}{dx} \\)

\n

", "advice": "

We are asked to differentiate a variety of functions, each consisting of a single term.

\n

We can do this using the \"Power Rule\" for differentiation:

\n

If   \\( y=ax^n \\)  then   \\( \\frac{dy}{dx} = n \\times a x^{n-1} \\)

\n

In plain language, \"multiply by the power, then reduce the power by one\".

\n

The \"Sum or Difference Rules\" also tell us that, as long as the terms are either added or subtracted, we can differentiate the function term by term.

\n

Then:

\n

a)

\n

\\( y= \\var{a1} x^{\\var{n1}} + \\var{a2} x^{\\var{n2}} +\\var{a3} \\)

\n

\\( \\frac{dy}{dx } =\\var{n1} \\times \\var{a1} x^{\\var{n1} - 1} + \\var{n2} \\times \\var{a2} x^{\\var{n2}-1}                  \\)

\n

The constant term  ( \\( \\var{a3} \\) )  can be seen as  \\( \\var{a3}x^0 \\) so will differentiate to \\( 0 \\times \\var{a3} x^{0-1} \\) which, of course equals zero. 

\n

\\( \\frac{dy}{dx } = \\simplify{ {n1}*{a1}*x^({n1}-1) + {n2}*{a2}*x^({n2}-1) } \\)

\n

\n

b)

\n

\\( \\simplify{y= {b1} x^{{m1}} + {b2} x^{{m2}}+{b3}x^{{m3}}+{b4} }  \\)

\n

\\( \\frac{dy}{dx } = \\var{m1} \\times \\var{b1} x^{\\var{m1} - 1} +\\var{m2} \\times \\var{b2} x^{\\var{m2} - 1}+\\var{m3} \\times \\var{b3} x^{\\var{m3} - 1}\\)

\n

The constant term  ( \\( \\var{b4} \\) )  can be seen as  \\( \\var{b4}x^0 \\) so will differentiate to \\( 0 \\times \\var{b4} x^{0-1} \\) which, of course equals zero. 

\n

\\( \\frac{dy}{dx } =\\simplify{  {m1}*{b1}*x^({m1}-1) + {m2}*{b2}*x^({m2}-1)+ {m3}*{b3}*x^({m3}-1)  } \\)

\n

\n

c)

\n

\\( \\simplify{y= {c1} x^{{p1}} + {c2} x^{{p2}} } \\)

\n

rem \\( \\frac{dy}{dx } = \\var{p1} \\times \\var{c1} x^{\\var{p1} - 1}  +\\var[fractionNumbers]{p2} \\times \\var{c2} x^{\\var[fractionNumbers]{p2} - 1}                \\)

\n

\\( \\frac{dy}{dx } = \\simplify{{p1}*{c1}*x^{{p1}-1} + {p2}*{c2}*x^{{p2}-1} } \\)

\n

 

\n

 

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List to allow random selection of fractional powers

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Differentiate the following:

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\\( y= \\var{a1} x^{\\var{n1}} + \\var{a2} x^{\\var{n2}} +\\var{a3} \\)

\n

\\( \\frac{dy}{dx } = \\)  [[0]]

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$ \\simplify{y= {b1} x^{{m1}} + {b2} x^{{m2}}+{b3}x^{{m3}}+{b4} }  $

\n

\\( \\frac{dy}{dx } = \\) [[0]]

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$ \\simplify{y= {c1} x^{{p1}} + {c2} x^{{p2}} }  $

\n

\\( \\frac{dy}{dx } = \\)  [[0]]

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Simple application of \"Power Rule\" to differentiate polynomials.

\n

Some co-efficients and powers are non-integer and some may be negative.

", "licence": "Creative Commons Attribution 4.0 International"}, "statement": "

The Power Rule

\n

You can find the derivative for powers of functions using the following rule:

\n

If   \\( y=ax^n \\)  then   \\( \\frac{dy}{dx} = n \\times a x^{n-1} \\) 

\n

The Sum or Difference Rules

\n

The derivative of   \\( f(x) + g(x) \\)  is  \\(  \\frac{df}{dx} + \\frac{dg}{dx} \\)          and          the derivative of   \\( f(x) - g(x) \\)  is  \\(  \\frac{df}{dx} - \\frac{dg}{dx} \\)

\n

", "advice": "

We are asked to differentiate a variety of functions, each consisting of a single term.

\n

We can do this using the \"Power Rule\" for differentiation:

\n

If   \\( y=ax^n \\)  then   \\( \\frac{dy}{dx} = n \\times a x^{n-1} \\)

\n

In plain language, \"multiply by the power, then reduce the power by one\".

\n

The \"Sum or Difference Rules\" also tell us that, as long as the terms are either added or subtracted, we can differentiate the function term by term.

\n

Then:

\n

a)

\n

\\( y= \\var{a1} x^{\\var{n1}} + \\var{a2} x^{\\var{n2}} +\\var{a3} \\)

\n

\\( \\frac{dy}{dx } =\\var{n1} \\times \\var{a1} x^{\\var{n1} - 1} + \\var{n2} \\times \\var{a2} x^{\\var{n2}-1}                  \\)

\n

The constant term  ( \\( \\var{a3} \\) )  can be seen as  \\( \\var{a3}x^0 \\) so will differentiate to \\( 0 \\times \\var{a3} x^{0-1} \\) which, of course equals zero. 

\n

\\( \\frac{dy}{dx } = \\simplify{ {n1}*{a1}*x^({n1}-1) + {n2}*{a2}*x^({n2}-1) } \\)

\n

\n

b)

\n

\\( \\simplify{y= {b1} x^{{m1}} + {b2} x^{{m2}}+{b3}x^{{m3}}+{b4} }  \\)

\n

\\( \\frac{dy}{dx } = \\var{m1} \\times \\var{b1} x^{\\var{m1} - 1} +\\var{m2} \\times \\var{b2} x^{\\var{m2} - 1}+\\var{m3} \\times \\var{b3} x^{\\var{m3} - 1}\\)

\n

The constant term  ( \\( \\var{b4} \\) )  can be seen as  \\( \\var{b4}x^0 \\) so will differentiate to \\( 0 \\times \\var{b4} x^{0-1} \\) which, of course equals zero. 

\n

\\( \\frac{dy}{dx } =\\simplify{  {m1}*{b1}*x^({m1}-1) + {m2}*{b2}*x^({m2}-1)+ {m3}*{b3}*x^({m3}-1)  } \\)

\n

\n

c)

\n

\\( \\simplify{y= {c1} x^{{p1}} + {c2} x^{{p2}} } \\)

\n

rem \\( \\frac{dy}{dx } = \\var{p1} \\times \\var{c1} x^{\\var{p1} - 1}  +\\var[fractionNumbers]{p2} \\times \\var{c2} x^{\\var[fractionNumbers]{p2} - 1}                \\)

\n

\\( \\frac{dy}{dx } = \\simplify{{p1}*{c1}*x^{{p1}-1} + {p2}*{c2}*x^{{p2}-1} } \\)

\n

 

\n

 

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\\( y= \\var{a1} x^{\\var{n1}} + \\var{a2} x^{\\var{n2}} +\\var{a3} \\)

\n

\\( \\frac{dy}{dx } = \\)  [[0]]

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$ \\simplify{y= {b1} x^{{m1}} + {b2} x^{{m2}}+{b3}x^{{m3}}+{b4} }  $

\n

\\( \\frac{dy}{dx } = \\) [[0]]

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$ \\simplify{y= {c1} x^{{p1}} + {c2} x^{{p2}} }  $

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\\( \\frac{dy}{dx } = \\)  [[0]]

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