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USE NUMERICAL APPROXIMATION TECHNIQUES TO EVALUATE DEFINITE INTEGRALS, WHERE APP

ID: 2886219 • Letter: U

Question

USE NUMERICAL APPROXIMATION TECHNIQUES TO EVALUATE DEFINITE INTEGRALS, WHERE APPROPRIATE, INCLUDING THE AREA UNDER A CURVE; USE RIEMANN SUMS, USING LEFT, RIGHT, AND MIDPOINT EVALUATION POINTS AND TRAPEZOIDAL SUMS TO APPROXIMATE DEFINITE INTEGRALS OF FUNCTIONS THROUGH ALGEBRAIC, GRAPHICAL, AND TABULAR REPRESENTATION, TABLE OF VALUES; DISCUSS ERROR IMPLICATIONS OF DIFFERENT METHODS Using 4 equal-width intervals, show that the trapezoidal rule is the average of the upper and lower sum estimates for [x2dx.

Explanation / Answer

Trapezoidal sum :

?x = (4 - 0)/4
?x = 4/4
?x = 1

Integral =(1/2) * (1) * ( f(0) + 2*f(1) + 2*f(2) + 2*f(3) + f(4) )

=(1/2) * (1) * ( 0 + 2*1 + 2*4 + 2*9 + 16 )

=22

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lower Sum :

Integral = (1) * ( f(0) + f(1) + f(2) + f(3) )


=(1) * ( 0 + 1 + 4 + 9 )

=14

Upper sum :

Integral =(1) * ( f(1) + f(2) + f(3) + f(4) )

=(1) * ( 1 + 4 + 9 + 16 )

=30

Find average of Upper sum and lower Sum as

average = (Upper sum +lower Sum)/2

=(30 +14)/2

=22

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Clearly, Trapezoidal rule is average of Upper sum and lower Sum .