differential

[Eng. Ahmed Said]

please answer me

find the point(s) on the curve Y = tan half X, X belongs to]0,360[ at which the tangent is perpendicular to the straight line Y=8-X

if the tangent to the curve of the circle X square+Y square=25 at the point (3,4) intersects the X-axis at the point C and intersectsthe Y -axis at the point D . prove that area of triangle COD equals 625/24 unit of area where O is the origin

If Y =2tanx/tan square x-1 Find
Y at X=15,then determine the measure of the posivite angle which the tangent to the curve at X=15 makes with the posivite direction of the Y-axis

if Y=(X square-2/X square+2)n, then prove that dy/dx =8nxy/X square-4
find dy/dx of each of the following composite functions

if V(t)=t square - 2t+3 is the relation between the velocity of a body V in cm/sec . and the time t in seconds.
calculate the average rate of change of the velocity of the body during the fifth second and evaluate the rate of change of the velocity at t=4