Thank you for using the timer - this advanced tool can estimate your performance and suggest more practice questions. We have subscribed you to Daily Prep Questions via email.

Customized for You

we will pick new questions that match your level based on your Timer History

Track Your Progress

every week, we’ll send you an estimated GMAT score based on your performance

Practice Pays

we will pick new questions that match your level based on your Timer History

Not interested in getting valuable practice questions and articles delivered to your email? No problem, unsubscribe here.

Thank you for using the timer!
We noticed you are actually not timing your practice. Click the START button first next time you use the timer.
There are many benefits to timing your practice, including:

if x is an integer, which value of x will yield the largest [#permalink]
31 Jul 2008, 09:42

if x is an integer, which value of x will yield the largest value for 5^-(x-3)^2

x= 3, -3, 9, -9, 0

Note: I saw something similar to this on my own exam..the numbers are made-up of course, the function is madeup also..just trying to test the concept..

regardless of x being greater or less than 3, the - in the front will switch the sign after squaring and make the exponent negative for sure. So we will have \frac{1}{5^n} where n = (x-3)^2

If x = 3, then we have -(3-3)^2, or 0^2 = 0, and -0 = 0, and so we then have \frac{1}{5^0} = 1/1 = 1.

Every other value listed for x will give an actual power making 5 * 5 * 5 * 5 or whatever that value becomes. With 5 being in the denominator, the largest fraction will be the one with the smallest denominator.

fresinha12 wrote:

if x is an integer, which value of x will yield the largest value for 5^-(x-3)^2

x= 3, -3, 9, -9, 0

Note: I saw something similar to this on my own exam..the numbers are made-up of course, the function is madeup also..just trying to test the concept..

_________________

------------------------------------ J Allen Morris **I'm pretty sure I'm right, but then again, I'm just a guy with his head up his a$$.

if x is an integer, which value of x will yield the largest value for 5^-(x-3)^2

x= 3, -3, 9, -9, 0

Note: I saw something similar to this on my own exam..the numbers are made-up of course, the function is madeup also..just trying to test the concept..

If I'm reading this right 5^-(x-3)^2 = 1/(5^(x-3)^2) That means you're trying to minimize 5^(x-3)^2 And from that, you're trying to minimize |x-3|

Of the answer choices, 3 would be the best choice.

if x is an integer, which value of x will yield the largest value for 5^-(x-3)^2

x= 3, -3, 9, -9, 0

Note: I saw something similar to this on my own exam..the numbers are made-up of course, the function is madeup also..just trying to test the concept..

to get the largest value of the function f(x)=5^-(x-3)^2

(x-3)^2 should be minimum.hence x=3 is the correct value
_________________

if x is an integer, which value of x will yield the largest value for 5^-(x-3)^2

x= 3, -3, 9, -9, 0

Note: I saw something similar to this on my own exam..the numbers are made-up of course, the function is madeup also..just trying to test the concept..

1) Largest value 5^-(x-3)^2 = when (x-3)^2 is least value..

(x-3) ^2 least value =0 --> when x=3.
_________________

Your attitude determines your altitude Smiling wins more friends than frowning

however on the exam..the ans choice listed didnt make (x-N)^2=0..i spent about 2 mins and just guessed..i think i was dubed by gmac..my exam was buggy..

however on the exam..the ans choice listed didnt make (x-N)^2=0..i spent about 2 mins and just guessed..i think i was dubed by gmac..my exam was buggy..

(x-N)^2=0 are you sure that power is 2 or -2 power.

(x-n)^-2 in this case.. answer could be different.
_________________

Your attitude determines your altitude Smiling wins more friends than frowning