Given the hyperbola with its left and right foci marked as F1 and F2 respectively. If there is a point P on the hyperbola such that the angle ∠F1PF2 is 90°, find the area of triangle ΔF1PF2, denoted as .
Solution
Since the equation of the hyperbola is given by , we have semi-major axis and semi-minor axis . The distance from the center to a focus can be calculated using .
According to the definition of a hyperbola, the absolute differences in distances from any point on a hyperbola to the foci is constant and equal to . Therefore, . Squaring both sides,
.
This equation can be rearranged to give:
.
Since we are given that the angle ∠F1PF2 is 90°, it follows from the Pythagorean theorem that:
.
Combining these two equations, we have:
,
which simplifies to:
.
The area of triangle ΔF1PF2 is given by one-half of the product of the lengths of the two segments forming the right angle, so:
.
Therefore, the area of the triangle is .
The problem is essentially asking us to find the product of the distances from the point P to each focus and then calculate the area of the triangle using the fact that there's a right angle formed at P. The key in solving this problem is to use the definition of a hyperbola and apply the Pythagorean theorem effectively.