SAT Math Problem Quadratic Equation Graphs #shorts

#shorts

Fast way to solve a question where you have to just look for the y-intercept of the equation.

[dashcamcompilationswithcomment]

Damn these questions can be solved within a few seconds, I wish we had the same level in turkey university exam system

[Anonymous-]

You could also use the midpoint formula to find the x intercept value which is 2 ( just average out the -2 and 6 on the x axis )

[cariboubearmalachy]

Once again, it takes 2s when you know the trick, but a minute to find the trick.

[CrackheadMagnate]

Because every answer is *0.5
Double y
Then subtract b or add depending on what's on the right then root of that number
Then you don't need to check all of them

[enjoywatchingyoutube]

If u had no answers given, u could use the vieta theorem wich states that for a function x^2+px+q
the sum of the roots equals -p
and the product of the roots equals q
In this case that would mean that p is -4 and q -12 wich leads to x^2-4x-12
under the condition that the y intecept is at 6 you only habe to multipy by -0.5
(Ofcourse u can swicht the sign before given that it is an inverse parabola in wich case u obly multipy by 0.5)
Wich leads to : -0.5(x^2-4x-12) wich is equal to Answer B or simply -0.5x^2+2x+6

[cariboubearmalachy]

You know that its B or C, since the midpoint of (-2, 0) and (6, 0) is (2, 0), so its y = d(x-2)^2+f. Then sub in x=0 and y = 6 to see which gives a correct answer.

[woozy]

I just received my exam scores today and I received a 1440 :) I can tell you that this is the exact method I used when I went against this problem.

[sheraah.-]

Just Plug in the values of x and y and see if it’s true that’s faster

[moeberry]

You can use the y- intercept or any one of the x- intercepts.

[chaoticstarfish]

(x+2)(x-6), and then multiply by -1/2.

[blizzard]

You don't need to find the whole answer of A, you know it's -1/2 * an odd number so you can skip directly to B

[ricky.-.]

You can find the answer without doing any math because the answers are in vertex form. You can just find the answer that has the same vertex as the graph and solve it in a few seconds.

[erinconley]

I let x=6 and it was easy to tell which answer would simplify to 0.

[waroftheworlds]

At first glance: it's shifted right by 2. So C or B.
It can't be C because the Y vertex is even. Was this problem supposed to have algebra involved? 🤣