Which one of the following is correct?
(A) `tan phi=r(d theta)/(dr),`
(B) `tan phi=r(dr)/(d theta)`
(C) `tan phi=(1)/(r)(d theta)/(dr),`
(D) `tan phi=(1)/(r)(dr)/(d theta)`

(sin (theta + phi))/( sin theta cos phi) = cot theta tan phi +1.

Prove: tan (45^(@)+ theta ) = (1 + tan theta)/( 1- tan theta )

If 3 tan theta tan phi=1, then (cos (theta-phi))/(cos (theta+phi)) is

If 3 tan theta tan phi=1, then (cos (theta-phi))/(cos (theta+phi)) is

If y=2 sin^(2) theta + tan theta then (dy)/(d theta) will be-

If a chord joining P(a sec theta, a tan theta), Q(a sec alpha, a tan alpha) on the hyperbola x^(2)-y^(2) =a^(2) is the normal at P, then tan alpha is (a) tan theta (4 sec^(2) theta+1) (b) tan theta (4 sec^(2) theta -1) (c) tan theta (2 sec^(2) theta -1) (d) tan theta (1-2 sec^(2) theta)

theta = tan^(-1) (2 tan^(2) theta) - tan^(-1) ((1)/(3) tan theta) " then " tan theta=

Prove: tan (45 ^(@) - theta ) =(1 - tan theta)/( 1 + tan theta)

Let theta = tan^(-1) ( tan . (5pi)/4) " and " phi = tan^(-1) ( - tan . (2pi)/3) then

If tan((theta)/(2))=5/2and tan((phi)/(2))=3/4, the value of cos(theta+phi), is