Question

If P = (x, y), F1 = (3, 0), F2 = (-3, 0) and 16 x2 + 25y2 = 400, then PF1 + PF2 equals

(a) 8 (b) 6

(c) 10 (d) 12

Answer 1

Step-by-step explanation:

Given 16 x²+ 25y² = 400

This can be written as x²/25 + y²/16 = 1

Hence, here we have a² = 25 and b² =16.

But, b² = a ²(1-e²)

16 = 25 (1-e²)

This gives 16/25 = (1-e²)

Hence, e² = 9/25.

The foci of the ellipse are (±ae, 0).

3 = a.3/5

Hence, a = 5.

PF1 + PF2 = major axis =2a = 10.

Answer 2

Answer:

these kind of answers are unknown to me

Step-by-step explanation:

Hi friend im new to brainly

please thank me thank me

so please dont ask