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Brynlee
12-30-2013, 05:26 AM
Hyperbola SAT Subject test Math level 2

Which of the following is a point of intersection between the hyperbola \frac{x^2}{4}-\frac{y^2}{25}=1 and the x-axis?

(A) (2,0)
(B) (4,0)
(C) (5,0)
(D) (25,0)
(E) (-5,0)

Thanks!

Thomas
12-30-2013, 05:27 AM
The point of intersection between the hyperbola \frac{x^2}{4}-\frac{y^2}{25}=1
and the x-axis can be found setting y equal to zero and then solve for x.

\frac{x^2}{4}-\frac{y^2}{25}=1 \Rightarrow \frac{x^2}{4}=1

\frac{x^2}{4}=1 \Rightarrow x^2 =4 \Rightarrow x=-2 \ or \ x=2

Therefore the correct answer is (A)

Brynlee
12-30-2013, 05:29 AM
Thanks Thomas