Math 11 Pre-Calculus – Mistakes as Learning Assignment (Unit 5)

 

1)    Original Question & Solution (Unit Five – Quadratic Functions & Equations: Skills Check, Question #5)
a)     Original Question
b)    Original Solution
c)     Reflection When I got the original solution, I was not aware that you needed to complete the square in order to find the final solution; I thought you could simply factor out the 5 and then get it into standard form but I soon discovered that it wasn’t possible because you would need a perfect square in order to get it into standard form. This was a broader conceptional error because I would have gotten the correct answer if I knew that the key component/ first step to getting the solution is to firstly start by completing the squares and not by factoring out the greatest common factor.
2)    Corrected Solution
a)     Correct Solution 1.     The first step is complete the square; you would take 5x^2+20x (from the original question and factor out the 5 just from 5x^2+20x (not including the negative 10), so now you’re left with y=5(x^2+4x)-10.

2.     Now, you need to completely complete the square; so, you would take the 2nd number factored in the bracket (in this case, 4) and multiply by ½ and then square it; (4 x ½) = 2^2 = 4. You’re now left with y=5(x^2+4x+4__)-10.

3.     After, you have got to minus the value that you have just found inside the brackets as well (-4) because then it will balance it out making it equal, so that it won’t mess with the original values. Now, we’ve got y=5(x^2+4x+4-4)-10.

4.     To complete the square, we have got to multiply the 5 by -4 to get it out of the bracket so we can form a perfect square; 5(x^2+4x+4)-20-10.

5.     We are now able to simplify it by simplifying the numbers out of the bracket (-20-10) and forming the perfect square; we now will get the final solution, 5(x+2)^2-30.

3)    Core Competency Reflection These past few mistakes as learning assignments have improved many of the core competencies; however, for this assignment specifically, my critical thinking has improved because it is needed to figure out each and every step and finding out exactly what I did wrong and finding the correct solution through each step, thoroughly by each detail; then, being able to teach it to someone by explaining my steps improved my understanding (even now). With that, I will also be analyzing my whole thought process and be able to see plenty of growth in my knowledge now.

 

 

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