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ACT 2 (questions #15-26)

Added May 02, 2020 •

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alrighty hey guys this is the second part of the ACT practice test 2 and we're starting with question number 15 right so here is question number 15 and 16 all right the diagonally opposite corners of a square have coordinates -1 2 and 5 to sew the easiest way to do this is almost really just catch those coordinates O negative 1 2 Men 5 2 and I just kind of did that so if you think about where the middle of that is this is only 6 units across so if I go back one two three years your middle point for Bertha Square your diagonals are perpendicular their the diagonals are also the midpoint there this would be going to go kind of through this here and remember this is three units this is 3 units if I come down 3 units I'm at 123 I'm right here so looking at these points this year or just distractors if you calculate that point that it's like .75 these don't even make any sense Thursday or just to kind of throw you off the negative one is over to the left here that doesn't make sense 1/2 doesn't make any sense those two positive to negative one. again just make us gets going to think about the ordered pairs think about the properties of a square and kind of where that leads you right number 60 this is just a degree in Durham even though this picture is drawn this way I think about that right angle this is your see your hypotenuse so make sure that you're setting that up correctly so we've got 10 squared and then administer 3 squared and that is equal to your AC squared + 500 squared - 9 squared so that is the square root of then the next one so we have done this is your special right triangles I know this kind of throws everybody off a little bit trying to remember the formulas and all that you can use the fact they're make you forget the formulas hopefully you remember a little bit about this but we've got each of the sides here are two this is two square roots of 2 which is also equal to X all right and then on this one they tell that the hypotenuse is 2x square roots of 2 so you're going to plug into square root of 2 in fraction to 2 square yards of two squares 2 * all that out we get for square roots of 2 time is it squirted to this gives us to support * 2 is 8 right to this is 8 and then your other two sides are going to be for square roots of 2 and then they want to know what is the perimeter of the larger triangle so you have eight on your hypotenuse and then Force words of 2 + I swear to you can add the twos words of to just add the front numbers together so 4 + 4 is 8 square root of 2 + 8 so that is going to give us are in Amber 18 soab is 5 so a b is v a d is for and B C is 13 so what I want you to focus on is the larger right triangle all right and don't worry about the for right now just do Pythagorean theorem all right if we do Pythagorean theorem undo 13 squared minus 5 squared and that's going to give you a hundred and forty-four take the square of that we get all of a to c okay and so from here all this is 12 and then you can find the to see so you're just going to subtract and that gives you 8 and then they want us to find the area of BCD so BCD is this triangle here all right and we can find that by doing 1/2 base times set the base is DC which is 8 and the height of the triangle is 5 so 8 * 5 is 40 and 1/2 of 40 is 20 + b number 19 so on this one again we've got a rectangle and a triangle so in the rectangle this is an eighth so we know this is 8 and we have right angles here this is a right angle and this is 60° C this is 30° so using your 30-60-90 this side is your dub side half of that this is 6 which makes this 6 and then decide across from 60 is 6 square roots of 30 they want what is the area of the entire quadrilateral is a rectangle part is 6 * 8 which is 48 the area of the triangle is 1/2 base times height so 6 * 6 squared so again you can do half of 6 which is three and then three times 6 gives you 18 square roots of 3 and then don't forget to add your 48 so since you have a radical on what number you can add those two 48 + 3018 sqrt 230 part number 20 is doing some trade but remember we got sign of ex says sign is opposite over hypotenuse opposite 1 hypotenuse is two cents sign of Acts this is cosine of why so these are complementary angles and if we do the sine of X and the cosine of Y cosine is adjacent over hypotenuse that it's this so that is one half uncommon easy one 2 is doing an ellipsis ellipses an oval however not to get into too much detail but if you put this in standard form when you divide by 15 so that you create a one on the end here putting this in that standard form we get x + 3 squared + 2 + 215 gives you 7 plus 1 - 4 squared / 5 ml is equal to 1 so the only thing you need to do to get the Centre though is take the numbers within the parentheses against the opposite sign so your Center would be a -3 and a positive for is this is not in our course will learn this in freak out integrated 3 or an Algebra 2 all right and then number 22 we are doing look at what possessed again your rise over run or rise number of physics so again if you are what do you want to go up this way it's the right or if you want to go down and left if I'm going down that's -6 and then left is -4 but those both make a positive motion since the two negatives cancel each other out for this 6/4 or three brighten and looking through each of your equations were trying to find one that has that same three halves and then also we want to look at where it crosses the y-axis so where is that Y intercept is not that positive so again if I move + 4x / that is not going to give us a 3/2 slope if I add 3x / and / 2 I'm going to also have an eight here which is not my y intercept so looking at the next one again if I take my two y ad 3x and bye-bye to I am going to get my rehabs here and into into 12 gets me sick so this is going to be the one that is working so I have my three have slope and I have my 6 y intercept alright 23 all right so for this when we have a large Cube 27 smaller cubes so 1 Q we have you have each cube is paid-up of sorry that's horrible the dimensions are 3 by 3 by 3 so again your volume is 3 cubed and then you have 27 smaller cubes so 27 x 27 is 729 and then you're just evaluating which one of these is equal to that one is cheap you want to grab this so if we graph this equation on your calculator you can look at the graph and you're going to see that it looks kind of apartment pool that's horrible, looks like so where are the values and negative so looking at this bottom section of the graph go from here all the way to hear these are negative so from -3 to is there where the values are negative All rights number 25 so this one you need a formula I use the phone 1/2 BC sign of a and this is formula for area of a triangle using a trig basically trig to help you out and because these are all equilateral triangles the value for a will be 60° B and C are the two sides that are on either side of the angle and because these are equilateral and he'll just use a number that you're going to make up so they're giving you a relationship between each of the triangles so that's what I'm going to do next so they're telling you that you have each of the three equilateral triangles for a dad is twice as long as BD so I let this be 2X bdbx and then e g b f f x okay so just to make this easy on me I let this be 4 which would make this 8 and let this be too and then I use those numbers to plug into this area formula 5 so I called he's like triangle a b and c just to kind of make that easier so if I was plugging in for triangle BDF you can let that be triangle be in the middle triangle so triangle a would be the smallest one do you want half of 2 * 2 * sine of 60° okay and that's a proximately way keep 7 and then triangle see which will be the largest triangle this side would be 8 + 4 because a 2d is 8 + indeed B is for so you have to add those about together so this whole side of the triangle is 12 right so that would be one half 12 * 12 and then sign of 60 that works out to 27.7 so then you have to divide to get the ratio and the ratio is 1 to 36 all right and I'm going to do one more cuz I will be running out of time and then I'll make one more small video for those black couple questions so for this one again we're looking at a factoring situations that we have x squared move everything to one side - 8x - 12 a squared what is 0 and you want to figure out which of these terms is going to help work out this problem so that we get our Solutions so all I did for this was just kind of look at what terms are going to work so we need 12 we need our difference to be a negative one so I have a 4 and a 3 again I need this to be a negative so minus and plus and then my Solutions I'm going to have a 4 and a negative 3 a and so positive for a and a negative 3 a is B all right and I cuz I don't make another video for the last few questions

Uploaded by Laurie Smithson.

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ACT 2 (questions #15-26)

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