Question
Question: The tangent to the curve 2y<sup>3</sup> = ax<sup>2</sup> + x<sup>3</sup> drawn at the point (a, a) ...
The tangent to the curve 2y3 = ax2 + x3 drawn at the point
(a, a) cuts l, m intercepts on coordinate axes where
l2 + m2 = 16. Then |a| is equal to –
A
31
B
30
C
28
D
16
Answer
30
Explanation
Solution
(dxdy)(a,a) = 6y22ax+3x2 = 6a25a2 = 65
equation of tangent ® y – a = 65 (x – a)
Ž (–5a)x + (6a)y = 1
given (–5a)2 + (6a)2= 1 Ž a2 = (25) (36)
|a| = 30