Q21.If u = sin-1 1 1 1 2 3 3 1 1 2 2 x + y x + y then ∂ ∂ u u x + y x y is:
Correct answer: 1 tan u 12 −
Q22.If ((())) ((()) u y ax y ax = φ + + ψ − = φ + + ψ − = φ + + ψ − = φ + + ψ − then 2 2 2 2 2 u u a x y ∂ ∂ − ∂ ∂ equal to:
Correct answer: 0
Q23.If 2 2 1 2 2 x y u sin x y − = + then u u x y ∂ ∂ + ∂ ∂ equal to
Correct answer: 0
Q24.If 3 3 1 tan x y u x y − + = + then du du x y dx dy + + equal to.
Correct answer: sin 2u
Q25.If ((())) ((()) f x cos logx = then (((()))) + × x f f x y y equal to.
Correct answer: ( ) ( )/2 f x f y
Q26.The complete integral of the equation p q 1 + = + =, where z z P,q x y ∂ ∂ = ∂ ∂ is
Correct answer: () 2 1 z ax a y c = + − +
Q27.If u=x3 +y3 + z3 + 3xyz, then x u u u y z x y z ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ + + ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ is equal to
Correct answer: 3u
Q28.If F is a differentiable point vector function and its second order partial derivative exists, then () (.) ∇ × ∇ × = ∇ × ∇ − ∇ × ∇ × = ∇ × ∇ − ∇ × ∇ × = ∇ × ∇ − ∇ × ∇ × = ∇ × ∇ − F F T. What is T?
Correct answer: None of these
Q29.If 1 x/ y u xytan (e), − = then u u x y ∂ ∂ + ∂ ∂ is equal to
Correct answer: 2u
Q30.z = φ (x + iy) + ψ ψ ψ (x – iy) is a solution of partial differential equation:
Correct answer: 2 2 z z 0 x y ∂ ∂ + = ∂ ∂
Q31.If u=xn-1 y f(y/x), then 2 2 2 u u x y x ∂ ∂ + ∂ ∂ ∂ is equal to?
Correct answer: (1) ∂ − ∂ u n x
Q32.Determine the general integral of the partial differential equation (())) () () y z p z x q x y + + + = + + + + = + + + + = + + + + = +
Correct answer: ()() ()() 2 2, 0 + + − + + − = x y z x y x y z x z φ
Q33.Solve the partial differential equation (()) 2 2 2 1 p y x qx + =
Correct answer: 1 2 2 2 1 2 z a x a y β = + + +
Q34.If x = rcosθ, y = rsinθ, Then the value of 2 2 x y ∂ θ ∂ θ ∂ θ ∂ θ ∂ θ ∂ θ ∂ θ ∂ θ + ∂ ∂ is:
Correct answer: 0
EnglishRajasthan TGT 2016
Q35.For the function 1 y z tan x − = consider the following statements: 1 z z S x y 0 x y ∂ ∂ ≡ + = ≡ + = ≡ + = ≡ + = ∂ ∂ 2 2 2 2 2 2 2 z z z S x 2xy y 0 x x y y ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ≡ + + = ≡ + + = ≡ + + = ≡ + + = ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ ∂ 2 2 3 2 2 z z S 0 x y ∂ ∂ ≡ + = ≡ + = ≡ + = ≡ + = ∂ ∂ Which of the following is true?
Correct answer: All S1, S2, S3
EnglishRajasthan TGT 2015
Q36.If 1 y u tan, x − = then the value of u u x y ∂ ∂ + ∂ ∂ is
Correct answer: 0
EnglishRajasthan TGT 2013
Q37.If F(u) = f(x,y,z) is the homogeneous function of degree n in x,y,z and ux= u x ∂ etc, then, xux+yuy+zuz=
Correct answer: F(u) n F'(u)
EnglishRajasthan TGT 2011 UP PCS (Pre) -1994
Q38.If 2 2 1 x y f sin x y − + = + then f f x x y ∂ ∂ + ∂ ∂ is equal to
Correct answer: tan f
EnglishRajasthan TGT 2011
Q39.If a function f(z) u(x,y) i (x,y) = + θ = + θ = + θ = + θ be analytic in a domain D, then Cauchy-Riemann equations are
Correct answer: u u; x y y x ∂ ∂θ ∂ ∂θ = − ∂ ∂ ∂ ∂
Q40.If 3 3 2 2 1 2 2 x y x y xy u tan x xy y − − + + − + + − + + − + + − = − + the value of u u x y ∂ ∂ + ∂ ∂ is:
Correct answer: 1 sin 2u 2