Answer Choices
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16
Explanation for Question 10 From the Math (No Calc) Section on the Official Sat Practice Test 3
Now number 10, we're told we have a parabola that has a certain equation. 2 Um, and it intersects with the line Y equals 25 at two points. 3 So essentially we've got, you know, our X, Y coordinate plane. 4 We've got a line that goes through 25, 5 and then there are two points where our parabola is going to intersect with 6 that. Right? And so we're asked what is the length of AB? 7 So we'll call this first point a we'll call the second one B. 8 And so really what we need to do here is find the Y or 9 not the Y coordinate the X coordinates of a and B. 10 We already know that the Y coordinate for those two points is 25, 11 but if we can find the X coordinates, then we can find the difference, 12 right? The difference in the distance between those two Xs. 13 And in order to do that, we're going to use this equation for the 14 parabola. 15 We know that Y is equal to 25. So instead of writing a Y 16 we can write, but 25 is equal to X minus 11 squared. 17 And then from here, we can just solve for X, 18 right? So a good first step is going to be the square root, 19 both sides of our equation. So we know that the side will be X 20 minus 11. Um, 21 but this side could be five, right? 22 Or it could be negative five because the square root of five can be 23 positive five or negative five. And so that's how we actually end up getting 24 the two points, right? Point a and point B is that when you take 25 that square root, you got a positive and a negative five. 26 So I'll add 11 to the s...