JAMB - Mathematics (1989 - No. 20)
What are K and L respectively if \(\frac{1}{2}\)(3y - 4x)2 = (8x2 + kxy + Ly2)
-12, \(\frac{9}{2}\)
-6, 9
6, 9
12, \(\frac{9}{2}\)
Penjelasan
\(\frac{1}{2}\)(3y - 4x)2 = (8x2 + kxy + Ly2)
\(\frac{1}{2}\)(9y2 - 24xy + 16x2) = 8x2 + kxy + Ly2
\(\frac{9}{2}\)y2 - 12xy) = kxy + Ly2
k = -12 ∴ L = \(\frac{9}{2}\)
\(\frac{1}{2}\)(9y2 - 24xy + 16x2) = 8x2 + kxy + Ly2
\(\frac{9}{2}\)y2 - 12xy) = kxy + Ly2
k = -12 ∴ L = \(\frac{9}{2}\)