Commerce (English Medium) कक्षा १२ - CBSE Important Questions

If x = `e^(x/y)`, then prove that `dy/dx = (x - y)/(xlogx)`.

The function f(x) = x |x| is ______.

If y = `sqrt(ax + b)`, prove that `y((d^2y)/dx^2) + (dy/dx)^2` = 0.

If f(x) = `{{:(ax + b; 0 < x ≤ 1),(2x^2 - x; 1 < x < 2):}` is a differentiable function in (0, 2), then find the values of a and b.

The derivative of x^2x w.r.t. x is ______.

If f(x) = `{{:(x^2"," if x ≥ 1),(x"," if x < 1):}`, then show that f is not differentiable at x = 1.

If y = tan x + sec x then prove that `(d^2y)/(dx^2) = cosx/(1 - sinx)^2`.

Show that the height of the cylinder of maximum volume, that can be inscribed in a sphere of radius R is `(2R)/sqrt3.`  Also, find the maximum volume.

Find the value of c in Rolle's theorem for the function `f(x) = x^3 - 3x " in " (-sqrt3, 0)`

Show that the function `f(x) = x^3 - 3x^2 + 6x - 100` is increasing on R

Show that the surface area of a closed cuboid with square base and given volume is minimum, when it is a cube.

The volume of a sphere is increasing at the rate of 3 cubic centimeter per second. Find the rate of increase of its surface area, when the radius is 2 cm

Prove that the semi-vertical angle of the right circular cone of given volume and least curved surface is \[\cot^{- 1} \left( \sqrt{2} \right)\] .

Prove that the function f : N → N, defined by f(x) = x² + x + 1 is one-one but not onto. Find the inverse of f: N → S, where S is range of f.

Evaluate : `intsin(x-a)/sin(x+a)dx`

Evaluate : ` int x^2/((x^2+4)(x^2+9))dx`

Evaluate : `∫_0^(π/2)(sin^2 x)/(sinx+cosx)dx`

Evaluate `∫_0^(3/2)|x cosπx|dx`

Evaluate :

`int(sqrt(cotx)+sqrt(tanx))dx`

Evaluate the definite integrals `int_0^pi (x tan x)/(sec x + tan x)dx`