INTRODUCTION, APPROXIMATION AND ERRORS http://numericalmethods.eng.usf.edu 01.01 INTRODUCTION http://numericalmethods.eng.usf.edu To find velocity from acceleration vs time data, the mathematical procedure used is A. Differentiation B. Integration 0% A. http://numericalmethods.eng.usf.edu 0% B. The form of the exact solution to A. B. C. D. . . . . 2 dy + 3 y = e − x , y (0) = 5 dx is Ae −1.5 x + Be − x Ae −1.5 x + Bxe − x Ae1.5 x + Be − x Ae1.5 x + Bxe − x 0% http://numericalmethods.eng.usf.edu A. 0% 0% B. C. 0% D. Given the f (x) vs x curve, and the magnitude of the areas as shown, the value of b ∫ f ( x)dx 0 A. B. C. D. -2 2 12 Cannot be determined y 5 a b 2 c x 7 25% A. http://numericalmethods.eng.usf.edu 25% 25% B. C. 25% D. A steel cylindrical shaft at room temperature is immersed in a dry-ice/alcohol bath. A layman estimates the reduction in diameter by using A. Less B. More C. Same ∆D = Dα∆T while using the value of the thermal expansion coefficient at -108oF. Seeing the graph below, the magnitude of contraction you as a USF educated engineer would calculate would be ______________than the layman’s estimate. 0% http://numericalmethods.eng.usf.edu 0% 0% END http://numericalmethods.eng.usf.edu 01.02 MEASURING ERRORS http://numericalmethods.eng.usf.edu The number of significant digits in 2.30500 is A. B. C. D. 3 4 5 6 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. The absolute relative approximate error in an iterative process at the end of the tenth iteration is 0.007%. The least number of significant digits correct in the answer is A. B. C. D. 2 3 4 5 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. Three significant digits are expected to be correct after an iterative process. The pre-specified tolerance in this case needs to be less than or equal to A. B. C. D. 0.5% 0.05% 0.005% 0.0005% 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. 01.03 SOURCES OF ERROR http://numericalmethods.eng.usf.edu The error caused by representing numbers such as 1/3 approximately is called A. Round-off error B. Truncation error 0% A. http://numericalmethods.eng.usf.edu 0% B. The number 6.749832 with 3 significant digits with rounding is A. B. C. D. 6.74 6.75 6.749 6.750 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. The error caused by using only a few terms of the Maclaurin series to calculate ex results mostly in A. Truncation Error B. Round off Error 0% A. http://numericalmethods.eng.usf.edu 0% B. The number 6.749832 with 3 significant digits with chopping is A. B. C. D. 6.74 6.75 6.749 6.750 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. END http://numericalmethods.eng.usf.edu 01.04 BINARY REPRESENTATION http://numericalmethods.eng.usf.edu (8)10=(?)2 A. B. C. D. 1110 1011 0100 1000 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. The binary representation of (0.3)10 is A. B. C. D. (0.01001……...)2 (0.10100……...)2 (0.01010……...)2 (0.01100……...)2 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. 01.05 FLOATING POINT REPRESENTATION http://numericalmethods.eng.usf.edu Smallest positive number in a 7 bit word where 1st bit is used for sign of number, 2nd bit for sign of exponent, 3 bits for mantissa and 2 bits for exponent A. B. C. D. 0.000 0.125 0.250 1.000 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. Five bits are used for the biased exponent. To convert a biased exponent to an unbiased exponent, you would A. B. C. D. add 7 subtract 7 add 15 subtract 15 0% A. 0% B. http://numericalmethods.eng.usf.edu 0% C. 0% D. END http://numericalmethods.eng.usf.edu 01.07 TAYLOR SERIES http://numericalmethods.eng.usf.edu Taylor series f ( x + h ) = f ( x ) + f ′( x )h + f ′′( x ) 2 f ′′′( x ) 3 h + h + 3! 2! is only valid A. if values of h are small B. if function and all its derivatives are defined and continuous at x C. if function and all its derivatives are defined and continuous in [x,x+h] 0% A. http://numericalmethods.eng.usf.edu 0% B. 0% C. END http://numericalmethods.eng.usf.edu EXTRA QUESTIONS http://numericalmethods.eng.usf.edu (01011)2 =(?)10 A. B. C. D. 7 11 15 22 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. The machine epsilon in a 7 bit number where 1st bit is used for sign of number, 2nd bit for sign of exponent, 3 bits for mantissa and 2 bits for 25% 25% 25% 25% exponent A. B. C. D. 0.125 0.25 0.5 1.0 A. B. http://numericalmethods.eng.usf.edu C. D. The number of significant digits in 0.0023406 is A. B. C. D. 4 5 6 7 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. The number of significant digits in 2350 is A. B. C. D. 3 4 5 3 or 4 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. To find velocity from location vs time data of the body, the mathematical procedure used is A. Differentiation B. Integration 0% A. http://numericalmethods.eng.usf.edu 0% B. Given y= sin(2x), dy/dx at x=3 is 1. 2. 3. 4. 0.9600 0.9945 1.920 1.989 0% 1 0% 0% 2 3 http://numericalmethods.eng.usf.edu 0% 4 In a five bit fixed representation, (0.1)10 is represented as (0.00011)2. The true error in this representation most nearly is A. B. C. D. 0.00625 0.053125 0.09375 9.5x10-8 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D. Largest positive number in a 7 bit number where 1st bit is used for sign of number, 2nd bit for sign of exponent, 3 bits for mantissa and 2 bits for exponent A. B. C. D. 1.875 4 7 15 0% A. 0% 0% B. C. http://numericalmethods.eng.usf.edu 0% D.