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Evaluating the limit of a function algebraically

Evaluate lim x 3 ( 2 x + 5 ) .

lim x 3 ( 2 x + 5 ) = lim x 3 ( 2 x ) + lim x 3 ( 5 ) Sum of functions property                       = 2 lim x 3 ( x ) + lim x 3 ( 5 ) Constant times a function property                       = 2 ( 3 ) + 5   Evaluate                       = 11
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Evaluate the following limit: lim x 12 ( 2 x + 2 ) .

26

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Finding the limit of a polynomial

Not all functions or their limits involve simple addition, subtraction, or multiplication. Some may include polynomials. Recall that a polynomial is an expression consisting of the sum of two or more terms, each of which consists of a constant and a variable raised to a nonnegative integral power. To find the limit of a polynomial function, we can find the limits of the individual terms of the function, and then add them together. Also, the limit    of a polynomial function as x approaches a is equivalent to simply evaluating the function for a .

Given a function containing a polynomial, find its limit.

  1. Use the properties of limits to break up the polynomial into individual terms.
  2. Find the limits of the individual terms.
  3. Add the limits together.
  4. Alternatively, evaluate the function for a .

Evaluating the limit of a function algebraically

Evaluate lim x 3 ( 5 x 2 ) .

lim x 3 ( 5 x 2 ) = 5 lim x 3 ( x 2 ) Constant times a function property                  = 5 ( 3 2 ) Function raised to an exponent property                  = 45
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Evaluate lim x 4 ( x 3 5 ) .

59

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Evaluating the limit of a polynomial algebraically

Evaluate lim x 5 ( 2 x 3 3 x + 1 ) .

lim x 5 ( 2 x 3 3 x + 1 ) = lim x 5 ( 2 x 3 ) lim x 5 ( 3 x ) + lim x 5 ( 1 ) Sum of functions                                 = 2 lim x 5 ( x 3 ) 3 lim x 5 ( x ) + lim x 5 ( 1 ) Constant times a function                                 = 2 ( 5 3 ) 3 ( 5 ) + 1 Function raised to an exponent                                 = 236 Evaluate
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Evaluate the following limit: lim x 1 ( x 4 4 x 3 + 5 ) .

10

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Finding the limit of a power or a root

When a limit includes a power or a root, we need another property to help us evaluate it. The square of the limit    of a function equals the limit of the square of the function; the same goes for higher powers. Likewise, the square root of the limit of a function equals the limit of the square root of the function; the same holds true for higher roots.

Evaluating a limit of a power

Evaluate lim x 2 ( 3 x + 1 ) 5 .

We will take the limit of the function as x approaches 2 and raise the result to the 5 th power.

lim x 2 ( 3 x + 1 ) 5 = ( lim x 2 ( 3 x + 1 ) ) 5                        = ( 3 ( 2 ) + 1 ) 5                        = 7 5                        = 16,807
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Evaluate the following limit: lim x 4 ( 10 x + 36 ) 3 .

64

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If we can’t directly apply the properties of a limit, for example in lim x 2 ( x 2 + 6 x + 8 x 2 ) , can we still determine the limit of the function as x approaches a ?

Yes. Some functions may be algebraically rearranged so that one can evaluate the limit of a simplified equivalent form of the function.

Finding the limit of a quotient

Finding the limit of a function expressed as a quotient can be more complicated. We often need to rewrite the function algebraically before applying the properties of a limit. If the denominator evaluates to 0 when we apply the properties of a limit directly, we must rewrite the quotient in a different form. One approach is to write the quotient in factored form and simplify.

Questions & Answers

Three charges q_{1}=+3\mu C, q_{2}=+6\mu C and q_{3}=+8\mu C are located at (2,0)m (0,0)m and (0,3) coordinates respectively. Find the magnitude and direction acted upon q_{2} by the two other charges.Draw the correct graphical illustration of the problem above showing the direction of all forces.
Kate Reply
To solve this problem, we need to first find the net force acting on charge q_{2}. The magnitude of the force exerted by q_{1} on q_{2} is given by F=\frac{kq_{1}q_{2}}{r^{2}} where k is the Coulomb constant, q_{1} and q_{2} are the charges of the particles, and r is the distance between them.
Muhammed
What is the direction and net electric force on q_{1}= 5µC located at (0,4)r due to charges q_{2}=7mu located at (0,0)m and q_{3}=3\mu C located at (4,0)m?
Kate Reply
what is the change in momentum of a body?
Eunice Reply
what is a capacitor?
Raymond Reply
Capacitor is a separation of opposite charges using an insulator of very small dimension between them. Capacitor is used for allowing an AC (alternating current) to pass while a DC (direct current) is blocked.
Gautam
A motor travelling at 72km/m on sighting a stop sign applying the breaks such that under constant deaccelerate in the meters of 50 metres what is the magnitude of the accelerate
Maria Reply
please solve
Sharon
8m/s²
Aishat
What is Thermodynamics
Muordit
velocity can be 72 km/h in question. 72 km/h=20 m/s, v^2=2.a.x , 20^2=2.a.50, a=4 m/s^2.
Mehmet
A boat travels due east at a speed of 40meter per seconds across a river flowing due south at 30meter per seconds. what is the resultant speed of the boat
Saheed Reply
50 m/s due south east
Someone
which has a higher temperature, 1cup of boiling water or 1teapot of boiling water which can transfer more heat 1cup of boiling water or 1 teapot of boiling water explain your . answer
Ramon Reply
I believe temperature being an intensive property does not change for any amount of boiling water whereas heat being an extensive property changes with amount/size of the system.
Someone
Scratch that
Someone
temperature for any amount of water to boil at ntp is 100⁰C (it is a state function and and intensive property) and it depends both will give same amount of heat because the surface available for heat transfer is greater in case of the kettle as well as the heat stored in it but if you talk.....
Someone
about the amount of heat stored in the system then in that case since the mass of water in the kettle is greater so more energy is required to raise the temperature b/c more molecules of water are present in the kettle
Someone
definitely of physics
Haryormhidey Reply
how many start and codon
Esrael Reply
what is field
Felix Reply
physics, biology and chemistry this is my Field
ALIYU
field is a region of space under the influence of some physical properties
Collete
what is ogarnic chemistry
WISDOM Reply
determine the slope giving that 3y+ 2x-14=0
WISDOM
Another formula for Acceleration
Belty Reply
a=v/t. a=f/m a
IHUMA
innocent
Adah
pratica A on solution of hydro chloric acid,B is a solution containing 0.5000 mole ofsodium chlorid per dm³,put A in the burret and titrate 20.00 or 25.00cm³ portion of B using melting orange as the indicator. record the deside of your burret tabulate the burret reading and calculate the average volume of acid used?
Nassze Reply
how do lnternal energy measures
Esrael
Two bodies attract each other electrically. Do they both have to be charged? Answer the same question if the bodies repel one another.
JALLAH Reply
No. According to Isac Newtons law. this two bodies maybe you and the wall beside you. Attracting depends on the mass och each body and distance between them.
Dlovan
Are you really asking if two bodies have to be charged to be influenced by Coulombs Law?
Robert
like charges repel while unlike charges atttact
Raymond
What is specific heat capacity
Destiny Reply
Specific heat capacity is a measure of the amount of energy required to raise the temperature of a substance by one degree Celsius (or Kelvin). It is measured in Joules per kilogram per degree Celsius (J/kg°C).
AI-Robot
specific heat capacity is the amount of energy needed to raise the temperature of a substance by one degree Celsius or kelvin
ROKEEB
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Source:  OpenStax, Precalculus. OpenStax CNX. Jan 19, 2016 Download for free at https://legacy.cnx.org/content/col11667/1.6
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