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Summary of differentiation rules

Given two functions, f ( x ) and g ( X ) we know that:

d d x b = 0
d d x ( x n ) = n x n - 1
d d x ( k f ) = k d f d x
d d x ( f + g ) = d f d x + d g d x

Rules of differentiation

  1. Find f ' ( x ) if f ( x ) = x 2 - 5 x + 6 x - 2 .
  2. Find f ' ( y ) if f ( y ) = y .
  3. Find f ' ( z ) if f ( z ) = ( z - 1 ) ( z + 1 ) .
  4. Determine d y d x if y = x 3 + 2 x - 3 x .
  5. Determine the derivative of y = x 3 + 1 3 x 3 .

Applying differentiation to draw graphs

Thus far we have learnt about how to differentiate various functions, but I am sure that you are beginning to ask, What is the point of learning about derivatives? Well, we know one important fact about a derivative: it is a gradient. So, any problems involving the calculations of gradients or rates of change can use derivatives. One simple application is to draw graphs of functions by firstly determine the gradients of straight lines and secondly to determine the turning points of the graph.

Finding equations of tangents to curves

In "Average Gradient and Gradient at a Point" we saw that finding the gradient of a tangent to a curve is the same as finding the gradient (or slope) of the same curve at the point of the tangent. We also saw that the gradient of a function at a point is just its derivative.

Since we have the gradient of the tangent and the point on the curve through which the tangent passes, we can find the equation of the tangent.

Find the equation of the tangent to the curve y = x 2 at the point (1,1) and draw both functions.

  1. We are required to determine the equation of the tangent to the curve defined by y = x 2 at the point (1,1). The tangent is a straight line and we can find the equation by using derivatives to find the gradient of the straight line. Then we will have the gradient and one point on the line, so we can find the equation using: y - y 1 = m ( x - x 1 ) from grade 11 Coordinate Geometry.

  2. Using our rules of differentiation we get: y ' = 2 x

  3. In order to determine the gradient at the point (1,1), we substitute the x -value into the equation for the derivative. So, y ' at x = 1 is: m = 2 ( 1 ) = 2

  4. y - y 1 = m ( x - x 1 ) y - 1 = ( 2 ) ( x - 1 ) y = 2 x - 2 + 1 y = 2 x - 1
  5. The equation of the tangent to the curve defined by y = x 2 at the point (1,1) is y = 2 x - 1 .

Curve sketching

Differentiation can be used to sketch the graphs of functions, by helping determine the turning points. We know that if a graph is increasing on an interval and reaches a turning point, then the graph will start decreasing after the turning point. The turning point is also known as a stationary point because the gradient at a turning point is 0. We can then use this information to calculate turning points, by calculating the points at which the derivative of a function is 0.

If x = a is a turning point of f ( x ) , then: f ' ( a ) = 0 This means that the derivative is 0 at a turning point.

Take the graph of y = x 2 as an example. We know that the graph of this function has a turning point at (0,0), but we can use the derivative of the function: y ' = 2 x and set it equal to 0 to find the x -value for which the graph has a turning point.

Questions & Answers

what is the stm
Brian Reply
How we are making nano material?
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What is STMs full form?
scanning tunneling microscope
how nano science is used for hydrophobicity
Do u think that Graphene and Fullrene fiber can be used to make Air Plane body structure the lightest and strongest. Rafiq
what is differents between GO and RGO?
what is Nano technology ?
Bob Reply
write examples of Nano molecule?
The nanotechnology is as new science, to scale nanometric
nanotechnology is the study, desing, synthesis, manipulation and application of materials and functional systems through control of matter at nanoscale
Is there any normative that regulates the use of silver nanoparticles?
Damian Reply
what king of growth are you checking .?
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
Stoney Reply
why we need to study biomolecules, molecular biology in nanotechnology?
Adin Reply
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
what school?
biomolecules are e building blocks of every organics and inorganic materials.
anyone know any internet site where one can find nanotechnology papers?
Damian Reply
sciencedirect big data base
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
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Akash Reply
it is a goid question and i want to know the answer as well
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s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
how can I make nanorobot?
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
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Source:  OpenStax, Siyavula textbooks: grade 12 maths. OpenStax CNX. Aug 03, 2011 Download for free at http://cnx.org/content/col11242/1.2
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