Explanation for Question 6 From the Math (Calc) Section on the 2019 April Sat
So for number six, we are given this function here and we are looking 2 for the one that is most suitable to indicate the X coordinates of the 3 X intercept of the graph. So all of these are 4 equal to the function. It tells us that. So that saves us time trying 5 to figure out if they are equal, 6 but it tells us they are. So we are good. 7 So now we want to look for which one most clearly tells 8 us the X intercepts, when solving for an X intercept in factored form, 9 you normally would take one of these factors and set it equal to zero, 10 right? So then I could solve for X 11 and get that X equals two. 12 However, this took me several steps to get there because of 13 the way that this factor was written. 14 So the one that would give me the answers, 15 the quickest would be B. 16 Since I can just look at these factors and know that if X minus 17 two is equal to zero, that means X is equal to two. 18 And if X plus three is equal to zero, then X is equal to 19 negative three. That's a much simpler and much faster way to find the X 20 intercept because for all of these other equivalent forms of the 21 function, I would have to do an extra step somewhere. 22 So you saw with this one, I would have to do the same thing 23 here. I would have to subtract six and then divide by two. 24 And then this one is a whole quadratic to solve. 25 So B gives both of the X intercepts in the simplest way. 26 So I can just look at that function and know exactly where the X 27 coordinates of the X intercepts are.