What to do with Quad Formula problems?

[Scottydsntkno15]

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I keep coming across problems in my physics practice (mainly projectile questions) where i need to use the quad formula, which just takes me too much time.

Are there any tricks to avoid the quad formula i should know about, or is there any fast way to try and do it besides rounding like crazy. The worst part for me is having to root large numbers.

thanks

 

[kehlsh]

there should be no problem that req's quad formula to solve

there MUST be some other way around

😡

 

[wiseman]

I second the above advice, according to the ExamKracker's audio cd, no questions on the MCAT will require the use of the quadratic equation.

 

[Biebs]

I keep coming across problems in my physics practice (mainly projectile questions) where i need to use the quad formula, which just takes me too much time.

Are there any tricks to avoid the quad formula i should know about, or is there any fast way to try and do it besides rounding like crazy. The worst part for me is having to root large numbers.

thanks

There really should no need to be using the quadratic equation. If you find yourself in a situation where it is needed, there is almost ALWAYS an easier way to solve these problems.

As for square rooting a large number, put it in scientific notation. This will make square rooting large numbers a lot easier.

For an example,

What is the square root of 400000?

SN: 40 x 10^4 (Make sure your exponent is an even number)
Square Root of 40 is between the square root of 6::36 and 7::49 (a little closer to 6), Square root of 10^4 is 10^2

So your answer should be something like 6.4x10^2 or 640.

Obviously you are estimating, but or the MCAT, that's all you need.

Hope this helps.

 

[Cinclus]

You won't need to use this on the MCAT.

 

[Ismet]

There's more than one way to express kinematic equations, if that's what you're getting at. You will not have to use the quadratic formula on the test (I actually don't even think I remember the whole thing! )

 

[phnerd1105]

Agreed. I came upon one in my BR physics book, and I just ignored the problem since you won't need to use it.

 

[coyotelime]

TBR gen chem part I specifically states that the quad formula will not be required in their equilibrium chapter... when you have something like 1-2x or something the quantity -2x will usually be small enough compared to the initial pressure/concentration that you can just designate it as insignificant.... no -2x, no FOIL, no quadratic equation, happy test taker. 👍

 

[Swagster]

I was like WTF when I came across it in BR physics, but in the explanation they showed how to get the answer without it and specifcially said that if you think you need to use the quad equation on the MCAT, you are doing it the long way. There's always an easier way using POE.

Don't use the quad equation.