03/09/2026
432 | Jacobian Problem Solved | If y₁=cosx₁, y₂=sinx₁cosx₂, y₃=sinx₁sinx₂cosx₃ Prove J | Engineering
Learn Jacobian of Three Trigonometric Functions with complete step by step proof. This video is made for http://B.Tech 1st Year, BSc Maths, MSc, JEE Advanced, CUET PG, and GATE Engineering Mathematics students who need to master determinant based problems on Jacobian and spherical coordinate transformations.
00:00 If y₁ = cosx₁ , y₂=sinx₁cosx₂, y₃ = sinx₂sinx₁cosx₃ then show that the Jacobian of y₁, y₂,y₃ with respect to x₁,x₂,x₃ is -sin³x₁sin²x₂sinx₃
01:30 Jacobian of y₁, y₂,y₃ with respect to x₁,x₂,x₃
01:40 Trick to write Formula of Jacobian of y₁, y₂,y₃ with respect to x₁,x₂,x₃
03:00 Theorem of Jacobian
05:00 Jacobian of y₁, y₂,y₃ with respect to x₁,x₂,x₃ is -sin³x₁sin²x₂sinx₃
We are given y₁ = cosx₁, y₂ = sinx₁cosx₂, y₃ = sinx₁sinx₂cosx₃. We have to show that the Jacobian of y₁, y₂, y₃ with respect to x₁, x₂, x₃ is equal to minus sin³x₁ sin²x₂ sinx₃. This pattern appears in spherical coordinates and multiple integrals.
00:00 If y₁ = cosx₁ , y₂=sinx₁cosx₂, y₃ = sinx₂sinx₁cosx₃ then show that the Jacobian of y₁, y₂,y₃ with respect to x₁,x₂,x₃ is -sin³x₁sin²x₂sinx₃
This is the standard transformation from spherical to cartesian like coordinates. To prove it we need to find all 9 partial derivatives and evaluate the 3x3 determinant.
01:30 Jacobian of y₁, y₂,y₃ with respect to x₁,x₂,x₃
Formula:
∂(y₁,y₂,y₃)/∂(x₁,x₂,x₃) = determinant of 3x3 matrix
Row1: ∂y₁/∂x₁ ∂y₁/∂x₂ ∂y₁/∂x₃
Row2: ∂y₂/∂x₁ ∂y₂/∂x₂ ∂y₂/∂x₃
Row3: ∂y₃/∂x₁ ∂y₃/∂x₂ ∂y₃/∂x₃
Find partials:
∂y₁/∂x₁ = minus sinx₁, ∂y₁/∂x₂ = 0, ∂y₁/∂x₃ = 0
∂y₂/∂x₁ = cosx₁cosx₂, ∂y₂/∂x₂ = minus sinx₁sinx₂, ∂y₂/∂x₃ = 0
∂y₃/∂x₁ = cosx₁sinx₂cosx₃, ∂y₃/∂x₂ = sinx₁cosx₂cosx₃, ∂y₃/∂x₃ = minus sinx₁sinx₂sinx₃
01:40 Trick to write Fo