SOLUTION: Points (a,3) and (-5,b) are on the circle x^2+y^2=34. Aisling says a=5 and b=-3. Do you agree or disagree? If you agree, explain why. If you disagree say what the possible values o

Algebra ->  Circles -> SOLUTION: Points (a,3) and (-5,b) are on the circle x^2+y^2=34. Aisling says a=5 and b=-3. Do you agree or disagree? If you agree, explain why. If you disagree say what the possible values o      Log On


   

Question 1116389: Points (a,3) and (-5,b) are on the circle x^2+y^2=34. Aisling says a=5 and b=-3. Do you agree or disagree? If you agree, explain why. If you disagree say what the possible values of a and b. Round to one decimal place if necessary.
thank you
Found 2 solutions by josgarithmetic, greenestamps:
Answer by josgarithmetic(39630) About Me  (Show Source):
You can put this solution on YOUR website!
(a,3):
x%5E2=34-y%5E2
x=0%2B-+sqrt%2834-y%5E2%29
x=0%2B-+sqrt%2834-3%5E2%29
x=0%2B-+sqrt%2834-9%29
x=0%2B-+5

Do both of these values work?
%285%29%5E2%2B3%5E2=34
25%2B9=34
34=34
-
%28-5%29%5E2%2B9=34
25%2B9=34
-
x=-5, or, x=5.
Either of these work in the equation.

You can solve for b, in the same way.

Answer by greenestamps(13215) About Me  (Show Source):
You can put this solution on YOUR website!


If (a,3) lies on the circle, then
a%5E2%2B3%5E2=34
a%5E2%2B9=34
a%5E2=25
a=5 or a=-5

If (-5,b) lies on the circle, then
%28-5%29%5E2%2Bb%5E2=34
25%2Bb%5E2=34
b%5E2=9
b=3 or b=-3

So if Aisling is saying that a HAS TO BE 5 and that b HAS TO BE -3, then he is wrong. a CAN BE 5, but it can also be -5; b CAN BE -3, but it can also be 3.