x | ||
f(x,y)=ln(x+ | ) | |
2y |
x | 2 x y + x | 2y + 1 | ||||
f(x , y) = ln( x + | ) = ln ( | ) = ln ( x*( | )) | |||
2y | 2 y | 2y |
2y | 2 y + 1 | 2 y + 1 | ||||
f'x ( x , y) = | * | = | = | |||
2 x y + x | 2y | 2 x y + x |
2y + 1 | 1 | |||
= | = | |||
x*( 2 y + 1) | x |
2y | 2 x*2y − ( 2 x y + x)*2 | |||
f'y ( x, y) = | * | = | ||
2 x y + x | (2y)2 |
2 y | 4 x y − 4 x y − 2 x | |||
= | * | = | ||
2 x y + x | (2 y)2 |
2y | − 2 x | −2 | ||||
= | * | = | = | |||
x*( 2 y + 1) | (2y)2 | (2 y+1)*(2y) |
−2 | ||
= | ||
4y2 +2y |