Group Abstract

Message Boards

WOLFRAM COMMUNITY

1.3K Views

1 Reply

0 Total Likes

View groups...

Follow this post

Share this post:

GROUPS:

Mathematics Calculus Wolfram Language

Not a valid variable in mahtematica

Minkyung Chun

Posted 11 months ago

Hi, I want to diffrentiate the eA1 by y. there is a lambda in the eA1, the lambda is sqrt(x^2+y^2) with some numbers. I got error named "D::ivar: (B Sqrt[x^2+y^2])/(2 c[HBar]) is not a valid variable." How can I fix it? Thanks. Clear All \[Lambda] = BSqrt[x^2 + y^2]/(2 c\[HBar]) H[\[Lambda]] D[log[H[\[Lambda]]], \[Lambda]] H2[x_, y_] := log[H[BSqrt[x^2 + y^2]/(2 c\[HBar])]/(2 c\[HBar])] eA1[x_, y_] = B^2y/(4c^2\[Lambda][x, y]) D[H2[x, y], BSqrt[x^2 + y^2]/(2 c\[HBar])] eA1[x, y] eB = D[eA1[x, y], y]

Hi, I want to diffrentiate the eA1 by y. there is a lambda in the eA1, the lambda is sqrt(x^2+y^2) with some numbers. I got error named "D::ivar: (B Sqrt[x^2+y^2])/(2 c[HBar]) is not a valid variable." How can I fix it? Thanks.

Clear All
\[Lambda] = B*Sqrt[x^2 + y^2]/(2 c\[HBar])
H[\[Lambda]]
D[log[H[\[Lambda]]], \[Lambda]]
H2[x_, y_] := log[H[B*Sqrt[x^2 + y^2]/(2 c\[HBar])]/(2 c\[HBar])]
eA1[x_, y_] = 
B^2*y/(4*c^2*\[Lambda][x, y]) D[H2[x, y], 
B*Sqrt[x^2 + y^2]/(2 c\[HBar])]
eA1[x, y]
eB = D[eA1[x, y], y]

POSTED BY: Minkyung Chun