SAT Math Question, x∆y?

Question

I was going over a practice SAT exam and I saw a problem involving x∆y, and I've never seen this before. Anyone familiar with what that means? The problem is x∆y = x^2 +xy +y^2, what is the value of (3∆1)∆1..

Someone was telling me that ∆ was the equivalent of ^, but if that was the case to get the y out of the exponent you'd have to take the natural log of both sides..

Any help much appreciated

Thanks a bunch, I get it now..

For whatever reason its not letting me resolve the question, so I can't choose a best answer =\

And thats because it hasn't been 4 hours, been a while since I've been on here lol

Answer 1

Someone asked this very same question in this forum
yesterday!
The solution goes like this:
First do the brackets:
3Δ1 = 3² + 3 + 1 = 13,
since you must substitute x = 3 and y = 1 in the formula
xΔy = x² + xy + y².
Now use x = 13 and y = 1 to get
13Δ1 = 13² + 13 + 1 = 183.
The answer is 183.

Answer 2

Whoever told you that were wrong. Most likely, it is just a made up symbol signifying example: 4 arrow 5 = 16 + 20 + 25 = 41

3 arrow 1= 9 + 3 + 1 = 13

13 arrow 1 = 169 + 13 + 1 = 183.

There's your answer.

Answer 3

I agree with previous answerer. This is just a matter of substitution and patience.
1) substitute 3 in place of x and 1 in place of y to get:
3^2 +3*1 +1^2= 9+3+1=13
2) you now have 13∆1
3) substitute 13 in place of x and 1 in place of y to get:
13^2 +13*1 +1^2= 169+13+1=183