Skip to main content

EASY CALCULUS



Take the function,

y = x^2

x        y=x^2
-3        9
-2        4
-1        1
0         0
1         1
2         4
3         9 


 If we draw the graph, we get a parabola.  Now we know how the function behaves. 







   I want to know if 'x' changes by 1[unity], What is a change in 'y' at any value of x.  That is, what is the rate of change of function at any point in the curve.  Is there any standard formula?  The question is easy to answer, if the function is linear or the graph is straight line.  The answer would be slope [gradient] of line and the slope will be the same at every point in the line. but Here we have parabolic relationship (refer figures).  

  Velocity is the rate of change of distance.Inflation is the rate of change of prices.Hence it is a very important quantity.

     Here, calculus come to our help.  It tells and proves that  if y=x^2,  dy/dx = 2x;  that is, the rate of change of function y= x^2 at any point is x is 2x.  Let us numerically verify it

Let x changes from 2 to 3;  unit change
hence y = x^2 changes from 4 to 9
Net change in y or rate of change of y =  9-4 = 5
average x value = [2+3]/2 = 2.5
From calculus, rate of change of y = 2x = 2*2.5 = 5
So it tallies.

Another example:
Let x changes from 10 to 11
Hence y changes from 100 to 121
Net change in y for unit change in x  = 121-100=21
average x = [10+11]/2= 10.5
rate of change is= 2x=2*10.5 = 21
So it tallies again.
  
 So the formula dy/dx = 2x works for any value for x (refer slopes in parabola graph).
Finding the rate of change of a function is called differentiation in calculus.  We have so many formula like this

examples:
y=sin x;  dy/dx=cos x

y=x^3;   dy/dx=3x^2 

y=e^x;   dy/dx=e^x   [no mistake]

Integration is the reverse of differentiation.

Integration of 2x=x^2
integration of cos x=sin x

Differentiation and integration are a two sides of a coin and they constitutes calculus.  It is the central blank of mathematics and it plays major roles in physics, engineering and economics.  

Comments

Popular posts from this blog

Your heart -you do not know

  Size and Location: The human heart is roughly the size of a clenched fist and is located slightly to the left of the center of the chest. Despite its relatively small size, the heart plays a crucial role in pumping blood throughout the entire body. Heartbeat Variability: The heart does not beat at a constant rate. The interval between heartbeats can vary, and this variability is considered a sign of a healthy heart. Factors such as breathing, emotions, and physical activity influence the heartbeat. Electrical Conduction: The heart's contractions are controlled by electrical impulses. The sinoatrial (SA) node, often called the "natural pacemaker," generates electrical signals that regulate the heartbeat and coordinate the pumping of blood. Blood Pumping Capacity: On average, the human heart pumps about 2,000 gallons (or 7,570 liters) of blood each day. Over a lifetime, this amounts to pumping enough blood to fill several Olympic-sized swimming pools. Heart Chambers and V...

THE WORK HORSE "="

    One cannot think of  a mathematical step without 'is equal to ' .  It balances right hand side and left hand side.  It aids simplification and manipulation of a mathematical expression. example: 2(A+B)  = C 2A+2B  = C         2A = C-2B           A = C-2B/ 2   In an electronic calculator,  the pressing of ' = " sign executes an asthmatic expression  or simply calculates.       In computer languages, it plays very important role.                                                                 A = B   When a computer looks at this expression, the value stored in the location named B is just transferred to the storage named A .  After execution both A and B will have the same value an...

How does your smart phone detect motion, steps, rotation, and location?

 How it works-1  An accelerometer in a smartphone is a microelectromechanical system (MEMS) device that measures acceleration and tilt. It works by detecting changes in motion by measuring the vibration or acceleration of the device. The accelerometer consists of a small mass suspended on a spring inside a sealed chamber. When the device is subjected to acceleration, the mass moves relative to the device, causing a change in capacitance that can be measured and processed by the smartphone's hardware. The accelerometer measures acceleration in three dimensions (x, y, and z) and provides data that the smartphone's software can use to determine the device's orientation, detect motion, and track changes in velocity and acceleration. The accelerometer is used for a variety of purposes in a smartphone, including screen rotation, motion tracking for games and fitness apps, and detecting the position of the device for navigation and location services. Additionally, it can be used t...