If `cos alpha cos beta=x/2, sinalpha sinbeta=y/2`, prove that:
`sec(alpha -ibeta)+sec(alpha-ibeta)=(4x)/(x^2-y^2)`
Concept: Review of Complex Numbers‐Algebra of Complex Number
If `z =log(e^x+e^y) "show that rt" - s^2 = 0 "where r"= (del^2z)/(delx^2),t=(del^2z)/(dely^2)"s"=(del^2z)/(delx dely)`
Concept: Review of Complex Numbers‐Algebra of Complex Number
If Z=tan^1 (x/y), where` x=2t, y=1-t^2, "prove that" d_z/d_t=2/(1+t^2).`
Concept: Review of Complex Numbers‐Algebra of Complex Number
Find the nth derivative of cos 5x.cos 3x.cos x.
Concept: Review of Complex Numbers‐Algebra of Complex Number
Evaluate : `Lim_(x→0) (x)^(1/(1-x))`
Concept: Review of Complex Numbers‐Algebra of Complex Number
If x = uv, y `=(u+v)/(u-v).`find `(del(u,v))/(del(x,y))`.
Concept: Review of Complex Numbers‐Algebra of Complex Number
If `y=2^xsin^2x cosx` find `y_n`
Concept: Review of Complex Numbers‐Algebra of Complex Number
Prove that log `[tan(pi/4+(ix)/2)]=i.tan^-1(sinhx)`
Concept: Logarithmic Functions
If `Z=x^2 tan-1y /x-y^2 tan -1 x/y del`
Prove that `(del^z z)/(del_ydel_x)=(x^2-y^2)/(x^2+y^2)`
Concept: Logarithmic Functions
If `u=x^2+y^2+z^2` where `x=e^t, y=e^tsint,z=e^tcost`
Prove that `(du)/(dt)=4e^(2t)`
Concept: Review of Complex Numbers‐Algebra of Complex Number
Show that the matrix A is unitary where A = `[[alpha+igamma,-beta+idel],[beta+idel,alpha-igamma]]` is unitary if `alpha^2+beta^2+gamma^2+del^2=1`
Concept: Inverse of a Matrix
If `z=tan(y-ax)+(y-ax)^(3/2)` then show that `(del^2z)/(delx^2)= a^2 (del^2z)/(dely^2)`
Concept: Partial Derivatives of First and Higher Order
Show that `ilog((x-i)/(x+i))=pi-2tan6-1x`
Concept: Logarithmic Functions
If `x=uv, y=u/v."prove that" jj,=1`
Concept: Partial Derivatives of First and Higher Order
Find the maxima and minima of `x^3 y^2(1-x-y)`
Concept: Maxima and Minima of a Function of Two Independent Variables
Find the stationary points of the function x3+3xy2-3x2-3y2+4 & also find maximum and minimum values of the function.
Concept: Maxima and Minima of a Function of Two Independent Variables
Examine the function `f(x,y)=xy(3-x-y)` for extreme values & find maximum and minimum values of `f(x,y).`
Concept: Maxima and Minima of a Function of Two Independent Variables
If `u=e^(xyz)f((xy)/z)` where `f((xy)/z)` is an arbitrary function of `(xy)/z.`
Prove that: `x(delu)/(delx)+z(delu)/(delz)=y(delu)/(dely)+z(delu)/(delz)=2xyz.u`
Concept: Partial Derivatives of First and Higher Order
Prove that `log(secx)=1/2x^2+1/12x^4+.........`
Concept: Logarithmic Functions
Show that sec h-1(sin θ) =log cot (`theta/2` ).
Concept: Logarithmic Functions