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Question
Select the correct option from the given alternatives:
If `"P"(pi/4)` is any point on he ellipse 9x2 + 25y2 = 225. S and S1 are its foci then SP.S1P =
Options
13
14
17
19
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Solution
17
Explanation;
[Hint: SP·S'P = a2sin2θ + b2cos2θ, where
a2 = 25, b2 = 9, θ = `pi/4`.]
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