Here's an alternative solution to the last problem: a+b+c is f(1). Since the parabola is open upwards, (9, -14) is the minimum value of f(x). Thus, f(1) (whatever it is) must be greater than 14 i.e. a+b+c > -14 Only choice d fulfills this criteria.

@derinwithaq5811

2 ай бұрын

that's actually very helpful, and much better than her very not rigorous "well it's probably mostly positive" explanation

@abdullah_abisola

Ай бұрын

That is mad I am blown away by this method I happened to try this on my own and landed at College Board's explanation but I also thought of this Cause Ik that 2a = 2nd diff 3a +b = 1st diff and a + b + c = 1st Term Thanks Alot

@psych0-shorts

Ай бұрын

Dude I was trying to look for a proof that a+b+c = f(1) for like 10 mins. Then I just plugged in a 1… I felt so stupid bro LMFAO

@bexqmish3699

Ай бұрын

Took me a sec to understand it, but that's really clever

@shlattrt

Ай бұрын

@@bexqmish3699 bro I don't get it can u help

Another very easy solution for question 2 I think would be to know that the Product = c / a so because c = ab and a = 57 , c/a = ab/57 = kab . The ab’s cancel out and we’re left with 1/57 = k

@harshithgogineni7093

7 ай бұрын

would've never thought of this. wow!

@armaan7381

6 ай бұрын

vietta's formula

@emmazhang2418

2 ай бұрын

why is a 57?

@savvas637

2 ай бұрын

@@emmazhang2418Because the formula for a quadratic equation is: ax^2 + bx +c = 0 so by comparing this to the equation given in the question a is 57

@vivianlee2509

18 күн бұрын

how do you know that c=ab ?

This right here is a goldmine!! Thanksss! rlly helpful!!

This was so helpful, thanks so much!

Thank u sooooo much ...u hv no idea how this really helped..

Thank you so much teacher it was so helpful to me❤. We are waiting for the part 2

Please make a video on "hard reading questions" on module 2

Becoming a calculator jockey is an under-rated strategy. A TI-84 Plus CE has functions in the APPS menu that bring high scores well within reach. You don’t need to be a math guru, just understand how to use the allowed tools.

Great tips! Thanks for sharing

@StrategicTestPrep

6 ай бұрын

Aw you’re welcome, Melissa!

You saved my Nigerian Life😩. I could kiss you. Thank you so much Ma'am. ♥️♥️✌️✌️

@meadowxchannel

3 ай бұрын

Shes about to save mine too

@stays4514

3 ай бұрын

​@@meadowxchannelyou're a Nigerian taking the sat this Saturday??

@NamGil-ed5bf

3 ай бұрын

@@stays4514yes

Thank you for what you do to help us, Laura. I've been watching your videos for a while now and I really appreciate what you do. But, I have a question on the second question. Why exactly did we set a and b as 1?

@StrategicTestPrep

7 ай бұрын

Great question - They’re just easier numbers to work with! You could set a and b as anything. And thank you I appreciate you watching 😊

for the last question would it also work if I add the minimum plus the x intercept plus the y intercept? It also gives 12 but I don't know if that is a correct way to solve.

Another was the day of things.

Your explanation for using the calculator was easy to comprehend but the solution to the questions were quite difficult to understand

oh my god the lighting how many lights do you have haha nevertheless, you always drop banger videos.

@StrategicTestPrep

9 ай бұрын

💙🙏💙

Hey, i have never used the desmos and my exam is on saturday. Do you advise that i should just stick with using my calculator or get familiar with the desmos?

@allisonturner5571

Ай бұрын

Hi random person, how did it end up going? In the same situation I'm wondering if the best is to use desmos as a last resort if I have no idea what to do.

Please I want to buy your course but is only English I want to buy because I can't afford both with the price given but I really want to buy the English

I have my exams on Oct 7 🥹 And I am currently hitting only 640 in Maths and 630 in English .I need to improve at least 80 points each in the next 27 days 🙂 Totally scared

@ucheshub23

9 ай бұрын

Seriously 😢.

@bidhyanshu

9 ай бұрын

@@ucheshub23 Promise brother 🥲 I wish I had started earlier

@khanhcatbi

8 ай бұрын

Hows it going now bro

@delightfulgenius4635

8 ай бұрын

What did you get up to?

@invisisense5464

6 ай бұрын

How was it?

Why is it a(x-9) for Practice 4, question 98?

@rodrigue9228

6 ай бұрын

This is the canonic form of the equation : y = a(x-A)^2+B where A and B are the x and y coordinate of the vertex.

8:36 I don't get why D is the answer. What if c was less than a and b, wouldn't that make a + b + c answer as positive?

@YTAlyx

3 ай бұрын

Her answer is right, but the method is not. Instead what you can do is write the equation in the form of a(x+b/2a)^2 + c - a*(b/2a)^2 (Squared form to find the vertex) and you have the values where b/2a=-9 And c - a*(b/2a)^2 = -14 Now find b and c in terms of a Substitute in a + b + c to get an equation in a You will get 64a-14 = ... To get a +ve value for "a". The ... (which is the answer) has to be lesser than 14, since they are all -ve values. Hence D is the answer

The first one isn’t that bad really. If it says that it only has one solution then it means that the lines only hit once. For that to happen y=-1.5 (the straight line) has to be just touching the bottom part of the parabola (height at vertex). We know that the vertex is x= -b/2a, and height y = f(-b/2a). From there its making the line’s height = to the vertex height.

why we give same number to a and b at question 95.They are actually not the same thing

@amena4887

6 ай бұрын

i have the same question !! im so confused

can we use Desmos during the exam?

@duck-vt4co

9 ай бұрын

It's on the test!

@McKylie151

9 ай бұрын

@@duck-vt4co ohh I see thank you♡

@StrategicTestPrep

9 ай бұрын

Yea you can!

I solved these problems like this: 92) Use Discriminant D=0; b^2-4ac = 0. Solving for a gives a = 14.5 95) Use x1*x2 = c/a = ab/57; k= 1/57. 98) V(9/-14); f(x) = a(x-9)^2 - 14 = ax^2 - 18ax + 81a - 14; a+b+c = 64a - 14. Since the parabola touches the x-axis twice and yV = -14, the limit as n->∞ is ∞, and, thus, a>0, from which follows that 64a - 14 > -14. The solution, hence, must be -12.

@azretomarrisbay8925

3 ай бұрын

Hi can i ask how did you get 64a-14?

@leonmaurice1746

3 ай бұрын

@@azretomarrisbay8925 Admittedly, my notation was plain wrong there, sorry about that. I should have written a new equation after f(x) = ax^2 -18ax +81a -14. The polynomial equality theorem for polynomials says that if two polynomials are equal to each other for all x∈𝔻, that the coefficients cn of each degree n of x, where n∈ℕ0, have to be equal as well (you don't really need to know this theorem, it's intuitive that the coefficients must be equal). We know that f(x)=ax^2 + bx + c and we derived that f(x)=ax^2 -18ax + 81a - 14 using the vertex form. The vertex and standard form are equivalent, so that ax^2 + bx + c = ax^2 -18ax + 81a -14. Now apply the polynomial equality theorem, from which follows that a=a, b=18a, c=81a-14. It immediately follows that a+b+c= 64a -14. The parabola is open upwards (you realize this when visualizing the vertex below the x-axis and the fact the graph touches the x-axis twice, the limit was a mere notational formality), so a>0. Thus, 64a-14 can never be smaller than -14. We, hence, get (D) -12 as our only option.

@azretomarrisbay8925

3 ай бұрын

@@leonmaurice1746 my bad, i missed the a+b+c part you wrote and thought u just got ax^2-18ax+81a-14=64a-14, now its clear thx for explanation🙏

@leonmaurice1746

3 ай бұрын

@@azretomarrisbay8925 you're welcome (and were right though btw, I did have it like that before, I corrected it after you commented)

@dundundun2383

3 ай бұрын

thank you for 98 because i also got 64a-14 but didnt know where to go from there

If you know a little bit of calculus, you don't even need desmos. y = -1.5 y = x^2 + 8x + a you can find the derivative of the second equation then set that equal to 0. then solve for x and that will give you the critical point. then insert that solution into x^2 + 8x + a = -1.5 then solve for a . and you've got it.

@StrategicTestPrep

5 ай бұрын

Love this!! Very cool

@rotimifr

2 ай бұрын

yes. well explained really helpful if you know how to get the derivative.

When will the sat score will publish? Of August 26 Digital

@obadaalibek732

9 ай бұрын

8th september after two days

Giving testers free access to desmos was the biggest mistake college board ever made. Hehehe…

could u do the hardest english questions?

@thx1136

9 ай бұрын

... with Desmos

but do the desmos on bluebook has a slider? i've done all of the practice tests but never notice there's a slider

@StrategicTestPrep

8 ай бұрын

There absolutely is a slider when you input a variable other than x or y

Hardest 😂

she keeps yapping so much.. such a time waste

Laura thank you so much for all your videos. You aren't just smart, you're also super pretty 🥹

@StrategicTestPrep

6 ай бұрын

Awwwww thank you so much!! 🥰