intro_to_symbol

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Unformatted text preview: Home > My Assignments > Intro to Symbolic Questions (Homework) About this Assignment SMALL BRIAN DIXON MA 241, section 009, Fall 2005 Instructor: Drew Pasteur North Carolina State University Due: Tuesday, August 23, 2005 11:01 PM EDT Description This assignment will Current Score: 17 out of 17 introduce you to symbolic Question Score questions. Instructions The focus is on recognizing when symbolic answers are desired, how to enter basic symbolic answers, how to preview your responses, and tips on special things that you will need to know when entering symbolic answers in this course. pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes 1. Enter this expression.: 6x + 11 = 6*x+11 [6*x+11] 2. Enter this expression. 5x - 9 = 5*x-9 [5*x-9] pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes 3. Many questions that require an expression for the answer also give you a chance to preview your answer to see if it "looks right". WebAssign attempts to understand what you have typed and to format it as it would appear in "normal" mathematical notation. Previewing your answer before you submit can sometimes help filter out mistakes you might occasionally make with syntax. Previewing an answer is optional. If you want to preview an answer, just type an answer in the answer box and then click the little "preview" symbol which is the icon to the right the answer box with the picture of an eye. Keep in mind that the reason for "previewing" is to help eliminate syntax errors, i.e. to make sure that what you have typed is a meanaingful mathematical expression and is what you intend. Try "previewing" in this problem. For this expression you'll need to use parentheses and the "^" symbol for exponentiation. Put the expression 4*x + 13 or 4x + 13 in parentheses, and then add "^6" to raise it to the appropriate power. (4x + 13)6 = (4*x+13)^6 [(4*x+13)^6] pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes 4. Using the necessary symbols, enter this expression. x11 + 6x6 - 2x3 - 6x + 15 = x^11+6*x^6-2*x^3-6*x+15 [x^11 + 6*x^6 - 2*x^3 - 6*x + 15] 5. Using the necessary symbols, enter this expression. 2x11 = 2*x^11 [2*x^11] pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: 6. Enter this expression. (Here you'll need parentheses around the exponent so that the fraction will be interpreted as the exponent. This is a good example of how previewing can be useful. Try your answer with and without parentheses around the exponent and notice what happens when you "preview" your answer in each case.) 7x1/13 = 7*x^(1/13) [7*x^(1/13)] 7. Enter the following expression: x^(1/6)-(9/x) [x^(1/6) - 9/x] 8. Enter this expression: (x^19)/36 [x^19/36] 9. Enter this expression: x^(1/4)(x+5) [x^(1/4) * (x+5)] 10. An optional notation for the square root function is "sqrt". Suppose x = y2 and you want to express y as a function of x. What you want to say is that y is the "square root of x." You can use either a fractional exponent or "sqrt" to say that. You can answer this question by typing Last Response View: All Responses Notes x^(1/2) or x^.5 or x^(.5) or sqrt(x). Try any of these. (Preview your answer.) y = sqrt(x) [sqrt(x)] IMPORTANT: You can enter things like sqrt(x), sqrt(y), or sqrt(2*x+4). But in all cases include the parentheses. WebAssign does NOT accept answers like sqrtx or sqrty. 11. Enter this expression: pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: (sqrt(x)-6)/(sqrt(x)+6) [(x^(1/2)-6)/(x^(1/2)+6)] 12. Enter this expression: (x + 5)5 (x + 2)4 (x+5)^5(x+2)^4 [(x+5)^5* (x+2)^4] 13. Enter this expression: ((x-5)/(x+2))^6 [( (x-5) / (x+2) )^6] 14. Enter this expression: Last Response View: All Responses Notes ((x^2-2)/(x^2+9))^3 [( (x^2 - 2) / (x^2 + 9) )^3] pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes 15. Symbolic questions generally require a higher degree of accuracy than numerical questions. For this reason it's better to type the expression in an "exact" form rather than to use decimal approximations. Suppose for example that you know that x = 3y and you want to express y in terms of x. You can type x/3 or 1/3 * x or x * 1/3, but typing .33 * x will get you into trouble. If you must use a decimal approximation in a symbolic question, make sure to use 5 or 6 decimal places of accuracy. (Sometimes you can get by with less, but it's risky.) If x = 3y, express y as a function of x: y = x/3 [x/3] pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses Notes pts subs 1 1/1 1/20 1/1 Viewing: Last Response View: All Responses 16. Some answers might require you to enter as part of your answer. In symbolic answers you just need to type the letters pi to represent . NEVER round to 3.14 because you will likely be counted as incorrect since symbolic answers require such a high degree of accuracy. Enter the following expression using the notation for . pi r^2 [pi * r^2] 17. Two other common things you might need to enter in symbolic form are log and natural log (ln). The way you enter these is pretty straight forward as long as you remember your parentheses. Some expamples are: log(10x), log(x), ln(10x), and ln(x). Enter the following expression using the proper notation. Notes (log(10*x))/(ln(x))+x^5 [log(10x)/ln(x) + x^5] Home My Assignments ...
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This note was uploaded on 10/21/2009 for the course MATH MA241 taught by Professor Hubbard during the Spring '09 term at N.C. Central.

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