Explanation for Question 10 From the Math (Calc) Section on the 2019 March Sat
Question 10 says the function F is defined above which of the following 2 is not an X intercept of the graph of the function in the X, 3 Y plane. So to find an X intercept, 4 all we have to do is set the Y value equal to zero. 5 So we're going to rewrite this equation as zero is equal to X plus 6 four times X minus one times two 7 X minus three. Now for this equation 8 to equal zero, any one of these sets of parenthesis could equal zero 9 because zero times anything is just zero, 10 right? So if any of these are equal to zero, 11 we would be at an X intercept. So I'm just going to take all 12 three of these sets of parentheses and set them equal to zero, 13 because I know these are all X intercepts once I solve for X. 14 So I'm just setting that up. 15 Now, now I'm going to solve for X to find all of the X 16 intercepts. So I can see if I subtract four from both sides that 17 there's an X intercept at zero at negative four, 18 zero there's an X intercept at X 19 is equal to one and X is equal to three over 20 two. So now let's define which of these is not actually an X intercept. 21 So negative four, zero is an X intercept. 22 So we can eliminate that. Uh, 23 one zero is an X intercept. 24 We can eliminate that. And three over two, 25 zero is also an Accenture. So, so we can eliminate that. 26 And that means that the only value here, that's not an X intercept is 27 negative two thirds, zero. So B is the correct answer.