Maths-
General
Easy
Question
P is a variable point on the ellipse += 1 with AA' as the major axis. Then, the maximum value of the area of the triangle APA' is-wor
- ab
- 2ab
- ab/2
- None of these
Hint:
find out the area in terms of the parametric coordinates and find the maxima.
The correct answer is: ab
ab
let the point P be (a cos t, b sin t)
area of triangle APA’ = ½ (2a)(bsint) = ab sin t
to find the maxima, we need to differentiate the above function
we get, ab cos(t) = 0
t=90
hence, maximum area = ab sin 90 = ab
when we differentiate an expression, we get the critical points where either maxima or minima can exist.
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