Explanation for Question 5 From the Math (No Calc) Section on the 2019 October Sat
Here in question number five, we're told that in the X, 2 Y plane, a dilation with the center. 3 Oh, by a scale factor of three. So here's the important information. 4 We have a dilation with a center at O which is the origin by 5 a factor of three transforms, 6 a B, C that triangle right here into triangle D F, 7 which of the following statements is not true now, 8 in order to solve this problem, 9 we first need to know what a dilation is. 10 And a dilation is essentially just a magnification, 11 right? You're taking a, um, a, 12 a shape or a picture that's in the coordinate plane, 13 and you're essentially making it larger by a certain factor. 14 So you're multiplying all the side lengths, 15 all of the distances by a certain number. 16 In this case, all of the numbers are multiplied by three, 17 right? So sidelines, AB times three gives us the side length 18 of the E and even still the, 19 um, the distance between the origin and a, 20 if you multiply that by three, that'll give us the distance between a and 21 D or not between a and D between the origin and D. 22 So this little picture in the corner has now been magnified by a factor 23 of three, to be this bigger picture. Now, 24 when you do that, when you multiply all the Cyberlinks by a factor, 25 that means that these two triangles are what you call similar. 26 And if two triangles are similar, that means that their Cyberlinks are different, 27 but they're different by a certain factor. Um, 28 so they're proportional t...