Lesson
05 of 23

💻 Differential Calculus(1)

Differential Calculus(1).

This lesson covers core applied mathematics concepts and their agricultural applications for BSc Agriculture learners.


MATHS :: Lecture 05 :: Differential Calculus(1)

DIFFERENTIATION

In all practical situations we come across a number of variables. The variable is one which takes different values, whereas a constant takes a fixed value. Let x be the independent variable. That means x can take any value. Let y be a variable depending on the value of x. Then y is called the dependent variable. Then y is said to be a function of x and it is denoted by y = f(x) For example if x denotes the time and y denotes the plant growth, then we know that the plant growth depends upon time. In that case, the function y=f(x) represents the growth function. The rate of change of y with respect to x is denoted by lec05_clip_image002.gifand called as the derivative of function y with respect to x.

S.No. Form of Functions y=f(x) lec05_clip_image002_0000.gif
  1. | Power Formula | xn | lec05_clip_image004.gif
  2. | Constant | C | 0
  3. | Constant with variable | Cy | lec05_clip_image006.gif
  4. | Exponential | ex | ex
  5. | Constant power x | ax | ax log a
  6. | Logirthamic | logx | lec05_clip_image008.gif
  7. | Differentiation of a sum| y = u + v where u and v are functions of x. | lec05_clip_image010.gif
  8. | Differentiation of a difference | y = u – v where u and v are functions of x. | lec05_clip_image012.gif
  9. | Product rule of differentiation | y = uv, where u and v are functions of x. | lec05_clip_image014.gif
  10. | Quotient rule of differentiation | y = lec05_clip_image016.gif , where u and v are functions of x. | lec05_clip_image018.gif where lec05_clip_image020.gif , lec05_clip_image022.gif

Example

  1. Differentiate each of the following function lec05_clip_image001.giflec05_clip_image003.giflec05_clip_image004_0000.giflec05_clip_image004_0001.gif

Solution

lec05_clip_image005.gif

  1. Differentiate following function lec05_clip_image006_0000.giflec05_clip_image003_0000.giflec05_clip_image004_0002.giflec05_clip_image004_0003.gif

Solution

Here is the derivative. lec05_clip_image007.giflec05_clip_image008_0000.giflec05_clip_image004_0004.giflec05_clip_image004_0005.gif

  1. Differentiate following function lec05_clip_image009.giflec05_clip_image010_0000.giflec05_clip_image004_0006.giflec05_clip_image004_0007.gif

Solution

lec05_clip_image011.giflec05_clip_image010_0001.giflec05_clip_image004_0008.giflec05_clip_image004_0009.gif diff. w.r.to x lec05_clip_image012_0000.giflec05_clip_image010_0002.giflec05_clip_image004_0010.giflec05_clip_image004_0011.gif MPSetEqnAttrs('eq0008','',3,[[90,34,13,-1,-1],[118,46,17,-1,-1],[148,57,21,-1,-1],[],[],[],[372,141,53,-3,-3]]); ExampleBegin(); 4.__ Differentiate the following functions. a) lec05_clip_image013.giflec05_clip_image014_0000.gif

Solution

MPSetEqnAttrs('eq0009','',3,[[84,18,5,-1,-1],[111,24,7,-1,-1],[139,31,8,-1,-1],[],[],[],[348,77,21,-3,-3]]) MPEquation() lec05_clip_image013_0000.giflec05_clip_image014_0001.giflec05_clip_image004_0012.giflec05_clip_image004_0013.gif MPSetEqnAttrs('eq0011','',3,[[76,23,5,-1,-1],[101,32,7,-1,-1],[127,40,8,-1,-1],[],[],[],[315,98,22,-3,-3]]) MPEquation() lec05_clip_image015.giflec05_clip_image016_0000.giflec05_clip_image004_0014.giflec05_clip_image004_0015.gif diff y w. r. to x MPSetEqnAttrs('eq0012','',3,[[154,27,9,-1,-1],[205,38,13,-1,-1],[257,47,16,-1,-1],[],[],[],[641,114,39,-3,-3]]) MPEquation() lec05_clip_image017.giflec05_clip_image018_0000.giflec05_clip_image004_0016.giflec05_clip_image004_0017.gif MPSetEqnAttrs('eq0012','',3,[[154,27,9,-1,-1],[205,38,13,-1,-1],[257,47,16,-1,-1],[],[],[],[641,114,39,-3,-3]]); MPSetEqnAttrs('eq0013','',3,[[132,62,28,-1,-1],[175,83,37,-1,-1],[218,105,47,-1,-1],[],[],[],[547,258,117,-3,-3]]); ExampleBegin(); 5. Differentiate the following functions. MPSetEqnAttrs('eq0014','',3,[[218,34,14,-1,-1],[289,45,19,-1,-1],[361,55,23,-1,-1],[],[],[],[905,141,58,-3,-3]]) MPEquation() MPSetEqnAttrs('eq0009','',3,[[84,18,5,-1,-1],[111,24,7,-1,-1],[139,31,8,-1,-1],[],[],[],[348,77,21,-3,-3]]);lec05_clip_image019.giflec05_clip_image020_0000.giflec05_clip_image004_0018.giflec05_clip_image004_0019.gif

MPSetEqnAttrs('eq0010','',3,[[130,17,6,-1,-1],[172,22,7,-1,-1],[216,27,8,-1,-1],[],[],[],[539,71,22,-3,-3]]) MPEquation()lec05_clip_image021.giflec05_clip_image019_0000.giflec05_clip_image020_0001.giflec05_clip_image004_0020.giflec05_clip_image004_0021.gif diff f(x) w r to x lec05_clip_image022_0000.giflec05_clip_image004_0022.gif lec05_clip_image004_0023.giflec05_clip_image023.gif

Derivatives of the six trigonometric functions

lec05_clip_image024.giflec05_clip_image025.giflec05_clip_image004_0024.giflec05_clip_image004_0025.gif

Example

1.__ Differentiate each of the following functions. lec05_clip_image026.giflec05_clip_image027.giflec05_clip_image004_0026.giflec05_clip_image004_0027.gif Solution We’ll just differentiate each term using the formulas from above. lec05_clip_image028.giflec05_clip_image029.giflec05_clip_image004_0028.giflec05_clip_image004_0029.gif 2.__ Differentiate each of the following functions lec05_clip_image030.giflec05_clip_image027_0000.giflec05_clip_image004_0030.giflec05_clip_image004_0031.gif Here’s the derivative of this function. lec05_clip_image031.giflec05_clip_image032.giflec05_clip_image004_0032.giflec05_clip_image004_0033.gif

Note that in the simplification step we took advantage of the fact that lec05_clip_image033.giflec05_clip_image034.giflec05_clip_image018_0001.giflec05_clip_image004_0034.giflec05_clip_image004_0035.gif to simplify the second term a little. 3.__ Differentiate each of the following functions lec05_clip_image035.giflec05_clip_image036.giflec05_clip_image004_0036.giflec05_clip_image004_0037.gif In this part we’ll need to use the quotient rule. lec05_clip_image037.giflec05_clip_image038.giflec05_clip_image004_0038.giflec05_clip_image004_0039.gif

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Summary Cheat Sheet

  • Focus on core formulas, definitions, and solved patterns from this lesson.
  • Practice stepwise derivations and numerical substitutions carefully.
  • Connect each concept to practical agricultural problem-solving contexts.

References

1 source

Primary classroom notes and standard BSc Agriculture applied mathematics references.

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